TY - JOUR
T1 - The long-time drift mobility in aSi:H
T2 - Optical bias and temperature dependence
AU - Pandya, R.
AU - Schiff, E. A.
AU - Conrad, K. A.
N1 - Funding Information:
INTRODUCTION Photocarrler drift mobllltles In a-SI:H have primarily been studied using the tlme-of-fllght (TOF) technique. There are two particularly noteworthy contrlbutlons of TOF experiments In recent years: the demonstratlon by TledJe, et al 1 that multlple-trapplng (MT) In exponentlal band tails accounts for the form and temperature-dependence of TOF photocurrent translents at short-times, and the recent quantltatlve demonstration by Street 2 using Ionger-tlme charge collection experlments of a photocarrler trapping process Involving neutral dangllng bonds (DO ) to form hlgher energy D-centers= DO + e-÷ DIn order to study deeper trapping and recomblnatlon processes It Is necessary to extend TOF drift mobility studles beyond their conventlonal time range (<10 -6 s at room temperature) and also to use much larger photoexcltatlon densities. For technical reasons, these experlments are not feaslble In the TOF conflguratlon. We have extended drift mobility studles far beyond the TOF limits listed above by uslng the coplanar electrode configuration. In thls paper we report the following results= ---The "deep traps" of Street are apparently fairly shallow (0.35 eV). We observe a smooth transition from multlple-trapplng In band tall states to multlple trapping In shallow states whlch are very probably the D-states of Street. Slmllar experlmental results have been reported earller by Huang, et a13; the process of shallow trapping Into D-states was proposed earlier to **Thls research was supported by NSF, The Research Corporation, and by Syracuse Unlverslty research funds.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1984/7
Y1 - 1984/7
N2 - The effects of optical bias and temperature on the drift-mobility of intrinsic aSi:H between 10-7 s and 1 s have been studied using coplanar electrode photocurrent transients. The drift mobility depends substantially upon optical bias over the entire time range, in contrast with the expectation from multiple-trapping in a fixed density of trap states. Shallow D- center traps formed from dangling bonds (D0) can account for the discrepancies if optical depopulation of the D0 is taken into account; this effect amounts to optical modification of the one-particle density of states.
AB - The effects of optical bias and temperature on the drift-mobility of intrinsic aSi:H between 10-7 s and 1 s have been studied using coplanar electrode photocurrent transients. The drift mobility depends substantially upon optical bias over the entire time range, in contrast with the expectation from multiple-trapping in a fixed density of trap states. Shallow D- center traps formed from dangling bonds (D0) can account for the discrepancies if optical depopulation of the D0 is taken into account; this effect amounts to optical modification of the one-particle density of states.
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U2 - 10.1016/0022-3093(84)90320-X
DO - 10.1016/0022-3093(84)90320-X
M3 - Article
AN - SCOPUS:0021464717
SN - 0022-3093
VL - 66
SP - 193
EP - 198
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
IS - 1-2
ER -