Strongly Temperature-Dependent Free-Energy Barriers Measured in a Polycrystalline Semiconductor

David L. Young; Richard S. Crandall

doi:10.1063/1.1977211

Strongly Temperature-Dependent Free-Energy Barriers Measured in a Polycrystalline Semiconductor

David L. Young, Richard S. Crandall

Chemistry and Nanoscience

National Renewable Energy Laboratory

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

17 Scopus Citations

Abstract

We measured temperature-dependent changes in free-energy barriers for emission of holes and electrons from metastable defects in polycrystalline CuIn1-x Gax Se2 using transient capacitance techniques. The free-energy barrier for holes increases by 17 meV, while the barrier for electrons decreases by 30 meV as the temperature increases from 380 to 400 K. The usual relation between thermal emission time and activation energy is reversed in this temperature range (we find a shorter emission time for the larger activation energy). Large entropy changes of +15 kB and -21 kB for the electron and hole emission, respectively, are calculated using transition-rate theory. These entropy terms in the free energy barrier account for the temperature dependences and the emission time inversion.

Original language	American English
Article number	262107
Pages (from-to)	1-3
Number of pages	3
Journal	Applied Physics Letters
Volume	86
Issue number	26
DOIs	https://doi.org/10.1063/1.1977211 https://doi.org/10.1063/1.1977211
State	Published - 27 Jun 2005

NREL Publication Number

NREL/JA-520-37765

Access to Document

Cite this

@article{ce79dbb2c9ce4541852dbff8ed8762c5,

title = "Strongly Temperature-Dependent Free-Energy Barriers Measured in a Polycrystalline Semiconductor",

abstract = "We measured temperature-dependent changes in free-energy barriers for emission of holes and electrons from metastable defects in polycrystalline CuIn1-x Gax Se2 using transient capacitance techniques. The free-energy barrier for holes increases by 17 meV, while the barrier for electrons decreases by 30 meV as the temperature increases from 380 to 400 K. The usual relation between thermal emission time and activation energy is reversed in this temperature range (we find a shorter emission time for the larger activation energy). Large entropy changes of +15 kB and -21 kB for the electron and hole emission, respectively, are calculated using transition-rate theory. These entropy terms in the free energy barrier account for the temperature dependences and the emission time inversion.",

author = "Young, {David L.} and Crandall, {Richard S.}",

year = "2005",

month = jun,

day = "27",

doi = "10.1063/1.1977211",

language = "American English",

volume = "86",

pages = "1--3",

journal = "Applied Physics Letters",

issn = "0003-6951",

publisher = "American Institute of Physics",

number = "26",

}

TY - JOUR

T1 - Strongly Temperature-Dependent Free-Energy Barriers Measured in a Polycrystalline Semiconductor

AU - Young, David L.

AU - Crandall, Richard S.

PY - 2005/6/27

Y1 - 2005/6/27

N2 - We measured temperature-dependent changes in free-energy barriers for emission of holes and electrons from metastable defects in polycrystalline CuIn1-x Gax Se2 using transient capacitance techniques. The free-energy barrier for holes increases by 17 meV, while the barrier for electrons decreases by 30 meV as the temperature increases from 380 to 400 K. The usual relation between thermal emission time and activation energy is reversed in this temperature range (we find a shorter emission time for the larger activation energy). Large entropy changes of +15 kB and -21 kB for the electron and hole emission, respectively, are calculated using transition-rate theory. These entropy terms in the free energy barrier account for the temperature dependences and the emission time inversion.

AB - We measured temperature-dependent changes in free-energy barriers for emission of holes and electrons from metastable defects in polycrystalline CuIn1-x Gax Se2 using transient capacitance techniques. The free-energy barrier for holes increases by 17 meV, while the barrier for electrons decreases by 30 meV as the temperature increases from 380 to 400 K. The usual relation between thermal emission time and activation energy is reversed in this temperature range (we find a shorter emission time for the larger activation energy). Large entropy changes of +15 kB and -21 kB for the electron and hole emission, respectively, are calculated using transition-rate theory. These entropy terms in the free energy barrier account for the temperature dependences and the emission time inversion.

UR - http://www.scopus.com/inward/record.url?scp=22144433014&partnerID=8YFLogxK

U2 - 10.1063/1.1977211

DO - 10.1063/1.1977211

M3 - Article

AN - SCOPUS:22144433014

SN - 0003-6951

VL - 86

SP - 1

EP - 3

JO - Applied Physics Letters

JF - Applied Physics Letters

IS - 26

M1 - 262107

ER -

Strongly Temperature-Dependent Free-Energy Barriers Measured in a Polycrystalline Semiconductor

Abstract

NREL Publication Number

Access to Document

Other files and links

Fingerprint

Cite this