Diffusion, drift, and recombination of holes in a-Si:H

R. Schwarz; F. Wang; S. Grebner; Q. Gu; E. A. Schiff

Diffusion, drift, and recombination of holes in a-Si:H

R. Schwarz, F. Wang, S. Grebner, Q. Gu, E. A. Schiff

Research output: Contribution to journal › Conference Article › peer-review

Abstract

We compare measurements in a-Si:H of ambipolar diffusion length L_amb (from steady-state photocarrier gratings (SSPG)) and hole drift χ(t) (from time-of-flight (TOF)). Using the response time t_R from small-signal photocurrent decay measurements, we find that the equation L_amb² = 2(kT/e)χ(t_R)/E is consistent with the measurements, where E is the electric field inducing hole drift in TOF. Several samples under different temperature and light intensity levels have been studied. This equation has several implications. Under the usual SSPG illumination conditions, electron-hole recombination occurs while holes are still occupying valence bandtail states; hence SSPG is not sensitive to hole capture by deep levels. Furthermore, the experiments show that the Einstein relation is valid for holes in a-Si:H. We are unaware of prior direct tests of this relation in an amorphous semiconductor.

Original language	English (US)
Pages (from-to)	427-436
Number of pages	10
Journal	Materials Research Society Symposium - Proceedings
Volume	377
State	Published - Dec 1 1995
Externally published	Yes
Event	Proceedings of the 1995 MRS Spring Meeting - San Francisco, CA, USA Duration: Apr 18 1995 → Apr 21 1995

ASJC Scopus subject areas

Materials Science(all)
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

Cite this

@article{f4325c60bcd444b593a990247907dc8d,

title = "Diffusion, drift, and recombination of holes in a-Si:H",

abstract = "We compare measurements in a-Si:H of ambipolar diffusion length Lamb (from steady-state photocarrier gratings (SSPG)) and hole drift χ(t) (from time-of-flight (TOF)). Using the response time tR from small-signal photocurrent decay measurements, we find that the equation Lamb2 = 2(kT/e)χ(tR)/E is consistent with the measurements, where E is the electric field inducing hole drift in TOF. Several samples under different temperature and light intensity levels have been studied. This equation has several implications. Under the usual SSPG illumination conditions, electron-hole recombination occurs while holes are still occupying valence bandtail states; hence SSPG is not sensitive to hole capture by deep levels. Furthermore, the experiments show that the Einstein relation is valid for holes in a-Si:H. We are unaware of prior direct tests of this relation in an amorphous semiconductor.",

author = "R. Schwarz and F. Wang and S. Grebner and Q. Gu and Schiff, {E. A.}",

year = "1995",

month = dec,

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language = "English (US)",

volume = "377",

pages = "427--436",

journal = "Materials Research Society Symposium - Proceedings",

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note = "Proceedings of the 1995 MRS Spring Meeting ; Conference date: 18-04-1995 Through 21-04-1995",

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TY - JOUR

T1 - Diffusion, drift, and recombination of holes in a-Si:H

AU - Schwarz, R.

AU - Wang, F.

AU - Grebner, S.

AU - Gu, Q.

AU - Schiff, E. A.

PY - 1995/12/1

Y1 - 1995/12/1

N2 - We compare measurements in a-Si:H of ambipolar diffusion length Lamb (from steady-state photocarrier gratings (SSPG)) and hole drift χ(t) (from time-of-flight (TOF)). Using the response time tR from small-signal photocurrent decay measurements, we find that the equation Lamb2 = 2(kT/e)χ(tR)/E is consistent with the measurements, where E is the electric field inducing hole drift in TOF. Several samples under different temperature and light intensity levels have been studied. This equation has several implications. Under the usual SSPG illumination conditions, electron-hole recombination occurs while holes are still occupying valence bandtail states; hence SSPG is not sensitive to hole capture by deep levels. Furthermore, the experiments show that the Einstein relation is valid for holes in a-Si:H. We are unaware of prior direct tests of this relation in an amorphous semiconductor.

AB - We compare measurements in a-Si:H of ambipolar diffusion length Lamb (from steady-state photocarrier gratings (SSPG)) and hole drift χ(t) (from time-of-flight (TOF)). Using the response time tR from small-signal photocurrent decay measurements, we find that the equation Lamb2 = 2(kT/e)χ(tR)/E is consistent with the measurements, where E is the electric field inducing hole drift in TOF. Several samples under different temperature and light intensity levels have been studied. This equation has several implications. Under the usual SSPG illumination conditions, electron-hole recombination occurs while holes are still occupying valence bandtail states; hence SSPG is not sensitive to hole capture by deep levels. Furthermore, the experiments show that the Einstein relation is valid for holes in a-Si:H. We are unaware of prior direct tests of this relation in an amorphous semiconductor.

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M3 - Conference Article

AN - SCOPUS:0029537762

SN - 0272-9172

VL - 377

SP - 427

EP - 436

JO - Materials Research Society Symposium - Proceedings

JF - Materials Research Society Symposium - Proceedings

T2 - Proceedings of the 1995 MRS Spring Meeting

Y2 - 18 April 1995 through 21 April 1995

ER -

Diffusion, drift, and recombination of holes in a-Si:H

Abstract

ASJC Scopus subject areas

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