高效 n-GaAs 光电电极由固态源近距离蒸气传输生长而成。

Efficient n-GaAs photoelectrodes grown by close-spaced vapor transport from a solid source.

机构信息

Department of Chemistry and the Materials Science Institute, University of Oregon, University of Oregon, Eugene, Oregon 97403, USA.

出版信息

ACS Appl Mater Interfaces. 2012 Jan;4(1):69-73. doi: 10.1021/am201631p. Epub 2011 Dec 15.

DOI:10.1021/am201631p

PMID:22136204

Abstract

n-GaAs films were grown epitaxially on n(+)-GaAs substrates by a close-spaced vapor transport method and their photoelectrochemical energy conversion properties studied. Under 100 mW cm(-2) of ELH solar simulation, conversion efficiencies up to 9.3% for CSVT n-GaAs photoanodes were measured in an unoptimized ferrocene/ferrocenium test cell. This value was significantly higher than the 5.7% measured for similarly doped commercial n-GaAs wafers. Spectral response experiments showed that the higher performance of CSVT n-GaAs films relative to the commercial wafers was due to longer minority carrier diffusion lengths (L(D)), up to 1,020 nm in the CSVT films compared to 260 nm in the commercial n-GaAs wafers. Routes to improve the performance of CSVT GaAs and the implications of these results for the development of scalable GaAs-based solar energy conversion devices are discussed.

摘要

采用近空间气相输运法在 n(+)-GaAs 衬底上外延生长 n-GaAs 薄膜，并研究了其光电化学能量转换特性。在未经优化的二茂铁/二茂铁阳离子测试电池中，在 100 mW cm(-2) 的 ELH 太阳模拟下，CSVT n-GaAs 光阳极的转换效率高达 9.3%。这一值明显高于对类似掺杂的商业 n-GaAs 晶片测量到的 5.7%。光谱响应实验表明，CSVT n-GaAs 薄膜相对于商业晶片的更高性能归因于更长的少数载流子扩散长度（L(D)），在 CSVT 薄膜中高达 1020nm，而在商业 n-GaAs 晶片为 260nm。讨论了提高 CSVT GaAs 性能的途径以及这些结果对开发可扩展的基于 GaAs 的太阳能转换器件的影响。