Photoluminescence characterization of Cu2Sn1-xGexS3 bulk single crystals
Photoluminescence characterization of Cu2Sn1-xGexS3 bulk single crystals
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DOI：
10.1063/1.5050033
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发表时间：
2018-09
期刊：
影响因子：
1.6
通讯作者：
Naoya Aihara;Kunihiko Tanaka
中科院分区：
文献类型：
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作者：
Naoya Aihara;Kunihiko Tanaka
Cu2Sn1-xGexS3（CTGS）由地球上储量丰富且无毒的元素组成，是一种很有前景的薄膜太阳能电池吸收层材料。在这项研究中，通过温度和激发功率相关的光致发光 (PL) 测量来研究具有不同锗含量的 CTGS 块状单晶的光学特性。在低温下，所有样品的 PL 光谱中均观察到激子和宽的缺陷相关带。这些 PL 谱带表明随着锗含量的增加而发生蓝移，这表明 CTGS 中形成了固溶体。宽带以供体-受体对（DAP）重组发光为主。 DAP 能带是由于任何合金成分的浅受体和相对深的施主之间的载流子转变所致。在室温下，所有样品均观察到带间 (BB) 重组发光。随着锗含量的增加，带隙能量从 0.933 eV 变化到 1.544 eV，这是通过 BB 带的光谱拟合确定的。此外，一个小的光学弯曲参数b，约为。确定了 0.1 eV，这表明 CTGS 的带隙能可以通过改变合金成分几乎线性地控制。因此，通过控制CTGS合金成分可以实现单结太阳能电池的最佳带隙能量。由地球丰富且无毒元素组成的Cu2Sn1-xGexS3（CTGS）是薄膜太阳能电池吸收层的一种有前途的材料。在这项研究中，通过温度和激发功率相关的光致发光 (PL) 测量来研究具有不同锗含量的 CTGS 块状单晶的光学特性。在低温下，所有样品的 PL 光谱中均观察到激子和宽的缺陷相关带。这些 PL 谱带表明随着锗含量的增加而发生蓝移，这表明 CTGS 中形成了固溶体。宽带以供体-受体对（DAP）重组发光为主。 DAP 能带是由于任何合金成分的浅受体和相对深的施主之间的载流子转变所致。在室温下，所有样品均观察到带间 (BB) 重组发光。随着锗含量的增加，带隙能量从 0.933 eV 变化到 1.544 eV，...
Cu2Sn1-xGexS3 (CTGS) which is composed of earth-abundant and non-toxic elements is a promising material for the absorber layer of thin-film solar cells. In this study, the optical properties of CTGS bulk single crystals with varying germanium content were investigated by temperature and excitation power dependent photoluminescence (PL) measurements. At low-temperature, excitons and broad defect-related bands were observed in the PL spectra from all samples. These PL bands indicate a blue-shift with an increase in the germanium content, which suggested the formation of solid-solutions in CTGS. The broad band was dominated by donor-acceptor pair (DAP) recombination luminescence. The DAP bands were due to the transition of carriers between shallow acceptors and relatively deep donors for any alloy composition. Band-to-band (BB) recombination luminescence was also observed from all samples at room temperature. The band gap energies were varied from 0.933 to 1.544 eV with an increase in the germanium content, which was determined by spectral fitting of the BB bands. In addition, a small optical bowing parameter b, of ca. 0.1 eV was determined, which indicates that the band gap energy of CTGS can be controlled almost linearly by varying the alloy composition. Therefore, the optimum band gap energy for single-junction solar cells can be achieved by control of the CTGS alloy composition.Cu2Sn1-xGexS3 (CTGS) which is composed of earth-abundant and non-toxic elements is a promising material for the absorber layer of thin-film solar cells. In this study, the optical properties of CTGS bulk single crystals with varying germanium content were investigated by temperature and excitation power dependent photoluminescence (PL) measurements. At low-temperature, excitons and broad defect-related bands were observed in the PL spectra from all samples. These PL bands indicate a blue-shift with an increase in the germanium content, which suggested the formation of solid-solutions in CTGS. The broad band was dominated by donor-acceptor pair (DAP) recombination luminescence. The DAP bands were due to the transition of carriers between shallow acceptors and relatively deep donors for any alloy composition. Band-to-band (BB) recombination luminescence was also observed from all samples at room temperature. The band gap energies were varied from 0.933 to 1.544 eV with an increase in the germanium content, ...