Open AccessEffect of oxygen implantation on microstructural and optical properties of ZnTe:O intermediate-band photovoltaic materials
Author(s) -
ZhiHui Kang,
Ruixia Gu,
Jiandong Ye,
Shulin Gu,
Fangfang Ren,
Shunming Zhu,
Shimin Huang,
Kun Tang,
Dongming Tang,
Yi Yang,
Rong Zhang,
Yi Zheng
Publication year - 2014
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.63.237103
Subject(s) - materials science , photoluminescence , band gap , optoelectronics , raman spectroscopy , ion implantation , exciton , amorphous solid , ion , condensed matter physics , crystallography , optics , chemistry , physics , organic chemistry
Group Ⅱ-VI and Ⅲ-V highly mismatched alloys are promising material systems in the application of high efficiency intermediate-band solar cell (IBSC), however, the key issues including band engineering of intermediate band still remain challenging. In this study, ZnTe:O alloys have been produced by isoelectric oxygen implantation into ZnTe single crystal, and the influences of implantation on the microstructural and optical properties of ZnTe:O have been investigated in detail. It is found that a proper dose of oxygen ions can lead to a compressive strain in the lattice and induce the formation of intermediate band located on the energy level of 0.45 eV below the conduction band. While a high dose of oxygen ions causes ZnTe surface layer to become amorphous and enhances the deep level emission around 1.6 eV, which is related to Zn vacancies. Results of resonant Raman and time-resolved photoluminescence spectra indicate that implantation induced intermediate band is related to the localized exciton emission bound to oxygen isoelectric trap, and the associated photo excited carriers have a relatively long decay time. This suggests that the reduction of lattice distortion and alloy disorder may be needed for converting localized states of the intermediate band into extended states, which is crucial to realize high efficiency ZnTe:O based IBSCs.