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arxiv: 2606.13622 · v1 · pith:FGH546M4new · submitted 2026-06-11 · ⚛️ physics.optics · cond-mat.mtrl-sci· physics.app-ph· physics.ins-det

Electric-Field Mapping of Optically Perturbed CdTe Radiation Detectors

Adriano Cola , Lorenzo Dominici , Antonio Valletta This is my paper

Pith reviewed 2026-06-27 05:35 UTC · model grok-4.3

classification ⚛️ physics.optics cond-mat.mtrl-sciphysics.app-phphysics.ins-det
keywords CdTe detectorsPockels effectelectric field mappingspace chargepolarizationSchottky detectorsdeep leveloptical perturbation
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The pith

A simple two-level model based on a dominant deep level fully accounts for the temporal and spatial dynamics of the electric field in optically perturbed CdTe Schottky detectors.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper maps the two-dimensional electric field inside a Schottky CdTe radiation detector by means of the Pockels effect and records how the field changes after an optical beam strikes the anode. Custom processing of the images yields vector maps that evolve during sequences of applied voltage and optical exposure. These maps match numerical simulations that invoke only a two-level system centered on one dominant deep level. The match shows that this minimal description already reproduces both the time course and the spatial pattern of the perturbation caused by space-charge buildup. The work thereby isolates the main mechanisms that produce non-equilibrium field distributions such as polarization.

Core claim

Pockels-effect imaging combined with a custom extraction routine produces electric-field vector maps across the detector volume. After optical exposure at the anode these maps display clear local perturbations whose time and space evolution agree quantitatively with simulations of a two-level model built around a single dominant deep level. The agreement demonstrates that this elementary model is sufficient to explain the full dynamics of the perturbed field and the associated polarization phenomena.

What carries the argument

Pockels-effect electro-optical imaging that extracts the internal electric-field vector, together with a two-level deep-level model that simulates the resulting space-charge dynamics.

If this is right

  • The same imaging and modeling sequence can be applied to predict performance limits of planar and electrode-segmented CdTe detectors.
  • The identified deep-level mechanism supplies a concrete target for material modifications aimed at reducing polarization.
  • The approach isolates space-charge accumulation as the dominant cause of field distortion under optical or radiation stress.
  • Temporal sequences of maps become a diagnostic tool for verifying detector stability under bias-exposure cycles.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The technique could be transferred to other wide-bandgap semiconductors to test whether a comparable two-level description governs their polarization behavior.
  • If the model parameters prove material-specific, they could guide the choice of compensation doping to shift the dominant deep level away from the mid-gap.
  • Combining the maps with charge-transport simulations would allow direct prediction of spectroscopic response degradation under the same optical conditions.
  • The method offers a route to quantify how electrode geometry alters the spatial reach of the perturbation.

Load-bearing premise

The Pockels-effect measurements accurately capture the true internal electric-field vector without significant distortion from surface states, optical absorption gradients, or mechanical stress induced by the optical beam itself.

What would settle it

If electric-field maps recorded at additional optical wavelengths or intensities deviate from the two-level model predictions by amounts larger than simulation uncertainty and cannot be reconciled by adjusting only the deep-level parameters, the claim that the simple model fully accounts for the dynamics would be refuted.

Figures

Figures reproduced from arXiv: 2606.13622 by Adriano Cola, Antonio Valletta, Lorenzo Dominici.

Figure 1
Figure 1. Figure 1: A sketch of the experiment: the line-focused optical excitation beam is incident on the anode side of the CdTe diode-like detector (left), whereas the 980 nm probe beam laterally crosses the detector in a cross-polarizer configuration. On the (right), an image of the transmitted intensity with both polarizers aligned and no voltage applied (Ppara). The optical perturbation beam comes from a supercontinuum … view at source ↗
Figure 2
Figure 2. Figure 2: Normalized Pockels images (left), corresponding electric-field maps (center) and central vertical profiles of the electric field (from anode to cathode) at selected instants (right): (a,e,i) under dark, just before optical irradiation; (b,f,j) under light, after 5 min of optical irradiation (red bar denotes the position and size of the irradiated region); (c,g,k) under dark, 2 s after the light switch-off;… view at source ↗
Figure 3
Figure 3. Figure 3: Experimental space charge: (a) the horizontal profile of the space charge (blue dots) and its fit by using a Gaussian function (cyan solid line). The profile is taken from the map below at a distance of 50 µm from the cathode. (b) Full map of the space charge at the end of the optical irradiation. The white color denotes values around zero, separating the regions bearing negative and positive charge. The e… view at source ↗
Figure 5
Figure 5. Figure 5: (a) Experimental and (b) simulated anode and cathode electric-field transients during the whole experiment (both fields are taken at 50 µm from the respective interface). The for￾ward/backward voltage steps to/from 600 V and the optical irradiation interval are highlighted. 3.5. Full Time–Space Charts Time–space charts of the horizontal electric-field profiles during the whole optical irradiation procedure… view at source ↗
Figure 1
Figure 1. Figure 1: Fig.1 [PITH_FULL_IMAGE:figures/full_fig_p014_1.png] view at source ↗
read the original abstract

In radiation detectors, the spatial distribution of the electric field plays a fundamental role in their operation. Access to this field distribution is of strategic importance, especially when investigating the perturbing effects induced by incident radiation. For example, one dangerous effect that prevents their proper operation is the accumulation of internal space charge. Here, we probe the two-dimensional electric field in a Schottky CdTe detector using the Pockels effect and report on its local perturbation after exposure to an optical beam at the anode electrode. Our electro-optical imaging setup, together with a custom processing routine, allows the extraction of the electric-field vector maps and their dynamics during a voltage bias-optical exposure sequence. The results are in agreement with numerical simulations, allowing us to confirm a two-level model based on a dominant deep level. Such a simple model is indeed able to fully account for both the temporal and spatial dynamics of the perturbed electric field. This approach thus allows a deeper understanding of the main mechanisms affecting the non-equilibrium electric-field distribution in CdTe Schottky detectors, such as those leading to polarization. In the future, it could also be used to predict and improve the performance of planar or electrode-segmented detectors.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript reports 2-D electric-field vector maps in a Schottky CdTe detector obtained via the Pockels effect before and after localized optical illumination at the anode. It extracts the spatial and temporal evolution of the perturbed field and compares these data to numerical simulations based on a two-level trap model with a dominant deep level, asserting that the simple model fully accounts for both the observed dynamics and the approach to polarization.

Significance. If the Pockels-derived field maps are shown to be free of significant systematic distortion and the agreement with simulation is placed on a quantitative footing, the work would supply a useful experimental benchmark for space-charge dynamics in CdTe detectors and a practical route to test minimal models of polarization. The combination of full-vector imaging with a parameter-light trap model is potentially valuable for both planar and segmented detector design.

major comments (2)
  1. [Abstract, §4] Abstract and §4 (comparison with simulation): the claim that the two-level model 'fully accounts' for the temporal and spatial dynamics is unsupported by any quantitative metric (fit residuals, χ², point-wise error maps, or parameter-sensitivity analysis). Without these, it is impossible to judge whether the agreement is substantive or the result of parameter adjustment to the same data.
  2. [§2, §3] §2 (Pockels imaging and processing) and §3 (results): no quantitative assessment or bounds are given for possible measurement artifacts arising from surface states, lateral absorption gradients, or photo-induced mechanical stress. Because the entire validation of the two-level model rests on the fidelity of these field maps, the absence of such checks is load-bearing for the central claim.
minor comments (2)
  1. [§2] Notation for the extracted field components (E_x, E_y) and the definition of the two-level parameters should be stated explicitly in the text rather than only in figure captions.
  2. [§3] The manuscript would benefit from a brief statement of how the optical-beam intensity and wavelength were chosen relative to the CdTe absorption edge.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive feedback. The comments highlight areas where additional rigor will improve the manuscript. We respond to each major comment below and will revise the text accordingly.

read point-by-point responses

  1. Referee: [Abstract, §4] Abstract and §4 (comparison with simulation): the claim that the two-level model 'fully accounts' for the temporal and spatial dynamics is unsupported by any quantitative metric (fit residuals, χ², point-wise error maps, or parameter-sensitivity analysis). Without these, it is impossible to judge whether the agreement is substantive or the result of parameter adjustment to the same data.

    Authors: We agree that the manuscript presents the model-experiment comparison primarily via visual inspection of the field maps and time traces. In the revision we will add quantitative metrics to §4, including χ² values computed on the vector field components, point-wise residual maps, and a short parameter-sensitivity study around the best-fit trap parameters. We will also revise the abstract and §4 wording from 'fully accounts' to 'accounts for the principal spatial and temporal features' to reflect the level of agreement actually demonstrated. revision: yes

  2. Referee: [§2, §3] §2 (Pockels imaging and processing) and §3 (results): no quantitative assessment or bounds are given for possible measurement artifacts arising from surface states, lateral absorption gradients, or photo-induced mechanical stress. Because the entire validation of the two-level model rests on the fidelity of these field maps, the absence of such checks is load-bearing for the central claim.

    Authors: We accept that explicit bounds on these systematics are needed. The revised §2 will include a new paragraph that (i) estimates the contribution of surface states from field maps recorded outside the illuminated region, (ii) bounds lateral absorption gradients using the known beam profile and literature absorption coefficients, and (iii) discusses photo-induced mechanical stress with reference to published piezo-optic coefficients for CdTe. Where experimental constraints prevent a precise numerical bound we will state the limitation explicitly. revision: yes

Circularity Check

0 steps flagged

No circularity: experimental maps compared to independent model simulation

full rationale

The abstract reports Pockels-derived 2-D field maps from a voltage-bias/optical-exposure sequence and states that these maps agree with numerical simulations of a two-level model, thereby confirming that the model accounts for the observed dynamics. No equations, parameter-fitting procedure, or self-citation chain is quoted that would reduce the agreement to a tautology or to a fit performed on the same data. The measurement chain supplies an external benchmark against which the model is tested; the central claim therefore rests on that comparison rather than on any of the enumerated circular patterns.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review; no explicit free parameters, axioms, or invented entities are stated. The two-level model is described as 'simple' and 'dominant deep level' but its concrete parameters and any fitting procedure are not provided.

pith-pipeline@v0.9.1-grok · 5750 in / 1143 out tokens · 21935 ms · 2026-06-27T05:35:11.880669+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

36 extracted references

  1. [1]

    Electron transport and charge induction in cadmium zinc telluride detectors with space charge build up under intense x-ray irradiation

    Bale, D.S.; Szeles, C. Electron transport and charge induction in cadmium zinc telluride detectors with space charge build up under intense x-ray irradiation. J. Appl. Phys. 2010, 107, 114512. [CrossRef]

    2010

  2. [2]

    Time-dependent electric field in Al/CdTe/Pt detectors

    Turturici, A.A.; Abbene, L.; Franc, J.; Grill, R.; Deˇdicˇ, V.; Principato, F. Time-dependent electric field in Al/CdTe/Pt detectors. Nucl. Instrum. Methods Phys. Res. Sect. A 2015, 795, 58–64. [CrossRef]

    2015

  3. [3]

    The polarization mechanism in CdTe Schottky detectors

    Cola, A.; Farella, I. The polarization mechanism in CdTe Schottky detectors. Appl. Phys. Lett. 2009, 94, 102113. [CrossRef]

    2009

  4. [4]

    Flux-dependent electric field changes in semi-insulating CdZnTe

    Franc, J.; Deˇdicˇ, V.; Zázvorka, J.; Hakl, M.; Grill, R.; Sellin, P.J. Flux-dependent electric field changes in semi-insulating CdZnTe. J. Phys. D Appl. Phys. 2013, 46, 235306. [CrossRef]

    2013

  5. [5]

    Electric Field and Current Transport Mechanisms in Schottky CdTe X-Ray Detectors under Perturbing Optical Radiation

    Cola, A.; Farella, I. Electric Field and Current Transport Mechanisms in Schottky CdTe X-Ray Detectors under Perturbing Optical Radiation. Sensors 2013, 13, 9414–9434. [CrossRef]

    2013

  6. [6]

    CdTe X-Ray Detectors under Strong Optical Irradiation

    Cola, A.; Farella, I. CdTe X-Ray Detectors under Strong Optical Irradiation. Appl. Phys. Lett. 2014, 105, 203501. [CrossRef]

    2014

  7. [7]

    Control of electric field in CdZnTe radiation detectors by above-bandgap light

    Franc, J.; Deˇdicˇ, V.; Rejhon, M.; Zázvorka, J.; Praus, P.; Touš, J.; Sellin, P.J. Control of electric field in CdZnTe radiation detectors by above-bandgap light. J. Appl. Phys. 2015, 117, 165702. [CrossRef]

    2015

  8. [8]

    De-polarization of a CdZnTe radiation detector by pulsed infrared light

    Deˇdicˇ, V.; Franc, J.; Rejhon, M.; Zázvorka, J.; Sellin, P. De-polarization of a CdZnTe radiation detector by pulsed infrared light. Appl. Phys. Lett. 2015, 107, 032105. [CrossRef]

    2015

  9. [9]

    Infrared LED Enhanced Spectroscopic CdZnTe DetectorWorking under High Fluxes of X-rays

    Pekárek, J.; Deˇdicˇ, V.; Franc, J.; Belas, E.; Rejhon, M.; Moravec, P.; Touš, J.; Voltr, J. Infrared LED Enhanced Spectroscopic CdZnTe DetectorWorking under High Fluxes of X-rays. Sensors 2016, 16, 1591. [CrossRef] [PubMed]

    2016

  10. [10]

    Electric field manipulation in Al/CdTe/Pt detectors under optical perturbations

    Turturici, A.A.; Franc, J.; Grill, R.; Deˇdicˇ, V.; Abbene, L.; Principato, F. Electric field manipulation in Al/CdTe/Pt detectors under optical perturbations. Nucl. Instrum. Methods Phys. Res. Sect. A 2017, 858, 36–43. [CrossRef]

    2017

  11. [11]

    Optical Writing and Electro-Optic Imaging of Reversible Space Charges in Semi-Insulating CdTe Diodes

    Cola, A.; Dominici, L.; Valletta, A. Optical Writing and Electro-Optic Imaging of Reversible Space Charges in Semi-Insulating CdTe Diodes. Sensors 2022, 22, 1579. [CrossRef] [PubMed]

    2022

  12. [12]

    Fast High-Flux Response of CdZnTe X-Ray Detectors by Optical Manipulation of Deep Level Defect Occupations

    Prokesch, M.; Bale, D.S.; Szeles, C. Fast High-Flux Response of CdZnTe X-Ray Detectors by Optical Manipulation of Deep Level Defect Occupations. IEEE Trans. Nucl. Sci. 2010, 57, 2397–2399. [CrossRef]

    2010

  13. [13]

    Improving the performance of CdZnTe detectors using infrared stimulation

    Dorogov, P.; Ivanov, V.; Loutchanski, A.; Grigorjeva, L.; Millers, D. Improving the performance of CdZnTe detectors using infrared stimulation. In Proceedings of the IEEE Nuclear Science Symposium Conference Record, Valencia, Spain, 23–29 October 2011; pp. 4557–4561. [CrossRef]

    2011

  14. [14]

    Improvement to the Carrier Transport Properties of CdZnTe Detector Using Sub-Band-Gap Light Radiation

    Luo, X.; Zha, G.; Xu, L.; Jie, W. Improvement to the Carrier Transport Properties of CdZnTe Detector Using Sub-Band-Gap Light Radiation. Sensors 2019, 19, 600. [CrossRef]

    2019

  15. [15]

    Study of polarization phenomena in Schottky CdTe diodes using infrared light illumination

    Sato, G.; Fukuyama, T.; Watanabe, S.; Ikeda, H.; Ohta, M.; Ishikawa, S.N.; Takahashi, T.; Shiraki, H.; Ohno, R. Study of polarization phenomena in Schottky CdTe diodes using infrared light illumination. Nucl. Instrum. Methods Phys. Res. Sect. A 2011, 652, 149–

    2011

  16. [16]

    Investigation of the electric field distribution in x-ray detectors by Pockels effect

    Cola, A.; Farella, I.; Auricchio, N.; Caroli, E. Investigation of the electric field distribution in x-ray detectors by Pockels effect. J. Opt. A Pure Appl. Opt. 2006, 8, S467. [CrossRef]

    2006

  17. [17]

    -S.; Schindler, S.M.; Eichelberger, A.C

    Bolotnikov, A.E.; Cook, W.R.; Harrison, F.A.; Wong, A. -S.; Schindler, S.M.; Eichelberger, A.C. Charge loss between contacts of CdZnTe pixel detectors. Nucl. Instrum. Methods Phys. Res. Sect. A 1999, 432, 326–331. [CrossRef]

    1999

  18. [18]

    Incomplete Charge Collection at Inter-Pixel Gap in Low- and High-Flux Cadmium Zinc Telluride Pixel Detectors

    Buttacavoli, A.; Principato, F.; Gerardi, G.; Cascio, D.; Raso, G.; Bettelli, M.; Zappettini, A.; Seller, P.; Veale, M.C.; Ab bene, L. Incomplete Charge Collection at Inter-Pixel Gap in Low- and High-Flux Cadmium Zinc Telluride Pixel Detectors. Sensors 2022, 22, 1441. [CrossRef] Sensors 2023, 23, 4795 13 of 13

    2022

  19. [19]

    A mechanism for dynamic lateral polarization in CdZnTe under high flux x-ray irradiation

    Bale, D.S.; Soldner, S.A.; Szeles, C. A mechanism for dynamic lateral polarization in CdZnTe under high flux x-ray irradiation. Appl. Phys. Lett. 2008, 92, 082101. [CrossRef]

    2008

  20. [20]

    Accumulated-carrier screening effect based investigation for the pixellated CdZnTe radiation detector

    Nie, L.; Xiao, S.; Li, M.; Wang, X.; Zhang, J.; Kong, W. Accumulated-carrier screening effect based investigation for the pixellated CdZnTe radiation detector. In Proceedings of the 2013 IEEE 12th International Conference on Cognitive Informatics and Cognitive Computing, New York, NY, USA, 16–18 July 2013; pp. 473–476. [CrossRef]

    2013

  21. [21]

    Further process of polarization within a pixelated CdZnTe detector under intense x-ray irradiation

    Wang, X.; Xiao, S.; Li, M.; Zhang, L.; Cao, Y.; Chen, Y. Further process of polarization within a pixelated CdZnTe detector under intense x-ray irradiation. Nucl. Instrum. Methods Phys. Res. Sect. A 2013, 700, 75–80. [CrossRef]

    2013

  22. [22]

    Local Polarization Phenomena in In-Doped CdTe X-Ray Detector Arrays

    Sato, T.; Sato, K.; Ishida, S.; Kin, M.; Hirooka, M.; Yamada, M.; Kanamori, H. Local Polarization Phenomena in In-Doped CdTe X-Ray Detector Arrays. IEEE Trans. Nucl. Sci. 1995, 42, 1513–1518. [CrossRef]

    1995

  23. [23]

    Characterization of the Charge Transport Uniformity of CdZnTe Crystals for Large-Volume Nuclear Detector Applications

    Soldner, S.A.; Narvett, A.J.; Covalt, D.E.; Szeles, C. Characterization of the Charge Transport Uniformity of CdZnTe Crystals for Large-Volume Nuclear Detector Applications. IEEE Trans. Nucl. Sci. 2004, 51, 2443–2447. [CrossRef]

    2004

  24. [24]

    Characterization of the Uniformity of High-Flux CdZnTe Material

    Veale, M.C.; Booker, P.; Cross, S.; Hart, M.D.; Jowitt, L.; Lipp, J.; Schneider, A.; Seller, P.; Wheater, R.M.; Wilson, M.D.; et al. Characterization of the Uniformity of High-Flux CdZnTe Material. Sensors 2020, 20, 2747. [CrossRef]

    2020

  25. [25]

    Polarization Studies of CdZnTe Detectors Using Synchrotron X-Ray Radiation

    Camarda, G.S.; Bolotnikov, A.E.; Cui, Y.; Hossain, A.; Awadalla, S.A.; Mackenzie, J.; Chen, H.; James, R.B. Polarization Studies of CdZnTe Detectors Using Synchrotron X-Ray Radiation. IEEE Trans. Nucl. Sci. 2008, 55, 3725–3730. [CrossRef]

    2008

  26. [26]

    Internal Electric-Field-Lines Distribution in CdZnTe Detectors Measured Using X-Ray Mapping

    Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Hossain, A.; Yang, G.; Yao, H.W.; James, R.B. Internal Electric-Field-Lines Distribution in CdZnTe Detectors Measured Using X-Ray Mapping. IEEE Trans. Nucl. Sci. 2009, 56, 791–794. [CrossRef]

    2009

  27. [27]

    Mapping of inhomogeneous quasi-3D electrostatic field in electro-optic materials

    Deˇdicˇ, V.; Fridrišek, T.; Franc, J.; Kunc, J.; Rejhon, M.; Roy, U.N.; James, R.B. Mapping of inhomogeneous quasi-3D electrostatic field in electro-optic materials. Sci. Rep. 2021, 11, 1–10. [CrossRef] [PubMed]

    2021

  28. [28]

    SentaurusTM Device User Guide. Version N-2017.09

    Sentaurus “SentaurusTM Device User Guide. Version N-2017.09.” Synopsys Inc., Sep. 2017. Available online: https://www. synopsys.com/silicon/tcad/device-simulation/sentaurus-device.html (accessed on 13 April 2023)

    2017

  29. [29]

    Charge transients by variable wavelength optical pulses in CdTe nuclear detectors

    Cola, A.; Farella, I.; Anni, M.; Martucci, M.C. Charge transients by variable wavelength optical pulses in CdTe nuclear detectors. IEEE Trans. Nucl. Sci. 2012, 59, 1569–1574. [CrossRef]

    2012

  30. [30]

    Study on Instability Phenomena in CdTe Diode-Like Detectors

    Farella, I.; Montagna, G.; Mancini, A.M.; Cola, A. Study on Instability Phenomena in CdTe Diode-Like Detectors. IEEE Trans. Nucl. Sci. 2009, 56, 1736–1742. [CrossRef]

    2009

  31. [31]

    On the relation between deep level compensation, resistivity and electric field in semi-insulating CdTe: Cl radiation detectors

    Cola, A.; Farella, I.; Pousset, J.; Valletta, A. On the relation between deep level compensation, resistivity and electric field in semi-insulating CdTe: Cl radiation detectors. Semicond. Sci. Technol. 2016, 31, 12LT01. [CrossRef]

    2016

  32. [32]

    Influence of Contacts on Electric Field in an Au/(CdZn)Te/Au Detector: A Simulation

    Franc, J.; James, R.B.; Grill, R.; Deˇdicˇ, V.; Belas, E.; Praus, P.; Prekas, G.; Sellin, P.J. Influence of Contacts on Electric Field in an Au/(CdZn)Te/Au Detector: A Simulation. IEEE Trans. Nucl. Sci. 2010, 57, 2349–2358. [CrossRef]

    2010

  33. [33]

    Nature of polarization in wide-bandgap semiconductor detectors under high-flux irradiation: Application to semi-insulating Cd1−xZnxTe

    Bale, D.S.; Szeles, C. Nature of polarization in wide-bandgap semiconductor detectors under high-flux irradiation: Application to semi-insulating Cd1−xZnxTe. Phys. Rev. B 1998, 77, 035205. [CrossRef] Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) ...

    1998

  34. [34]

    The corresponding profiles at x=0 are also reported aside each map

    Simulated Electric Field maps/profiles at different instants Figure S1 Simulated Electric Field maps corresponding to the experimental ones in Fig.1: a) under dark, just before optical irradiation; b) under light, after 5 min of optical irradiation; c) under dark, 2 sec after the light switch-off; d) under dark 15min after the light switch-off. The corres...

  35. [35]

    The peak of positive space charge under light corresponds to the maximum trapping occurring where the electric field becomes negligible near the cathode

    Simulated space charge profiles at different instants Figure S2 Simulated space charge profiles at x=0 (center of optical irradiation) at different instants: under dark just before light (black), under light, after 5 min of optical irradiation (green), under dark, 15 min after the light switch -off (blue). The peak of positive space charge under light cor...

  36. [36]

    Some relevant parameters of the simulations including those of the 2-level model

    Simulation parameters Table S1. Some relevant parameters of the simulations including those of the 2-level model. CdTe Shallow donor level (fully ionized) Concentration Nd 2.8x1013cm-3 Acceptor deep level Energy Ec-Ea 0.725eV Concentration Na 5.8x1013cm-3 Electr. capture cross section σea 1x10-18cm2 Hole capture cross section σha 1.5x10-19cm2 Electron mob...