Delta doping and positioning effects of type II GaSb quantum dots in GaAs solar cell

被引：2

作者：

Asirvatham, Juanita Saroj James ^{[1
]}

Fujita, Hiromi ^{[2
]}

Fernández-Delgado, N. ^{[3
]}

Herrera, M. ^{[3
]}

Molina, S.I. ^{[3
]}

Marshall, Andrew R. J. ^{[1
]}

Krier, Anthony ^{[1
]}

机构：

[1] Physics Department, Lancaster University, Lancaster

[2] Magnetic Sensors Process Technology and Development Department, Asahi-Kasei Microdevices, Fuji, 416-8501, Shizuoka

[3] Departamento de Ciencia de los Materiales e I.M. y Q.I., Instituto de Microscopía Electrónica y Materiales, Puerto Real, 11510, Cádiz

来源：

Energy Materials: Materials Science and Engineering for Energy Systems | 2015年 / 10卷 / 04期

关键词：

Delta doping; Gallium antimonide; Molecular beam epitaxy; Open-circuit voltage (V[!sub]oc[!/sub]); Photocurrent; Photoresponse; Quantum dots; Solar cells;

D O I：

10.1080/14328917.2015.1115807

中图分类号：

学科分类号：

摘要：

GaSb quantum dot (QD) solar cell structures were grown by molecular beam epitaxy on GaAs substrates. We investigate the reduction in open-circuit voltage and study the influence of the location of QD layers and their delta doping within the solar cell. Devices with 5 layers of delta-doped QDs placed in the intrinsic, n- and p-regions of a GaAs solar cell are experimentally investigated, and the deduced values of Jsc, Voc, fill factor, efficiency (η) are compared. A trade-off is needed to minimize the Voc degradation while maximizing the short circuit current density (Jsc) enhancement due to sub-bandgap absorption. The voltage recovery is attributed to the removal of the QDs from the high-field region which reduces SRH recombination. The devices with p- or n-doped QDs placed in the flat band potential (p- or n-region) show a recovery in Jsc and Voc compared to devices with delta-doped QDs placed in the depletion region. However, there is less photocurrent arising from the absorption of sub-band gap photons. Furthermore, the long wavelength photoresponse of the n-doped QDs placed in the n-region shows a slight improvement compared to the control cell. The approach of placing QDs in the n-region of the solar cell instead of the depletion region is a possible route towards increasing the conversion efficiency of QD solar cells. © W. S. Maney & Son Ltd. 2016.

引用

页码：512 / 516

页数：4

共 7 条

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