Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Carrier extraction from GaSb quantum rings in GaAs solar cells using direct laser excitation
AU - James Asirvatham, Juanita
AU - Fujita, Hiromi
AU - Carrington, Peter
AU - Marshall, Andrew
AU - Krier, Anthony
PY - 2014/4
Y1 - 2014/4
N2 - The authors report on the analysis of the hole escape mechanisms from type-II GaSb quantum rings (QRs) embedded within the active region of a GaAs single junction solar cell. When the solar cell is excited by using a 1064 nm infrared laser with excitation energy lower than the bandgap of the GaAs matrix, photogenerated electron-hole pairs are created directly within the GaSb QRs. The QR photocurrent exhibits a linear dependence on the excitation intensity over several decades. The thermal activation energy was found to be weakly dependent on the incident light level and increased by only a few meV over several orders of excitation intensity. The magnitude of the relative absorption in the author's QRs when directly probed by using a 1064 nm laser with an incident power density of approximate to 2.6 W cm(-2) is found to be approximate to 1.4 x 10(-4) per layer. The thermal escape rate of the holes was calculated and found to be approximate to 10(11) to 10(12) s(-1), which is much faster than the radiative recombination rate 10(9) s(-1). This behaviour is promising for concentrator solar cell development and has the potential to increase solar cell efficiency under a strong solar concentration.
AB - The authors report on the analysis of the hole escape mechanisms from type-II GaSb quantum rings (QRs) embedded within the active region of a GaAs single junction solar cell. When the solar cell is excited by using a 1064 nm infrared laser with excitation energy lower than the bandgap of the GaAs matrix, photogenerated electron-hole pairs are created directly within the GaSb QRs. The QR photocurrent exhibits a linear dependence on the excitation intensity over several decades. The thermal activation energy was found to be weakly dependent on the incident light level and increased by only a few meV over several orders of excitation intensity. The magnitude of the relative absorption in the author's QRs when directly probed by using a 1064 nm laser with an incident power density of approximate to 2.6 W cm(-2) is found to be approximate to 1.4 x 10(-4) per layer. The thermal escape rate of the holes was calculated and found to be approximate to 10(11) to 10(12) s(-1), which is much faster than the radiative recombination rate 10(9) s(-1). This behaviour is promising for concentrator solar cell development and has the potential to increase solar cell efficiency under a strong solar concentration.
U2 - 10.1049/iet-opt.2013.0062
DO - 10.1049/iet-opt.2013.0062
M3 - Journal article
VL - 8
SP - 76
EP - 80
JO - IET Optoelectronics
JF - IET Optoelectronics
SN - 1751-8768
IS - 2
ER -