Valence band offset at the CdS/Cu2ZnSnS4 interface probed by x-ray photoelectron spectroscopy
Valence band offset at the CdS/Cu2ZnSnS4 interface probed by x-ray photoelectron spectroscopy
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DOI：
10.1088/0022-3727/46/17/175101
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发表时间：
2013-05
期刊：
影响因子：
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通讯作者：
A. Santoni;F. Biccari;C. Malerba;M. Valentini;R. Chierchia;A. Mittiga
中科院分区：
文献类型：
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作者：
A. Santoni;F. Biccari;C. Malerba;M. Valentini;R. Chierchia;A. Mittiga
用X射线光电子能谱（XPS）研究了CdS/Cu_2ZnSnS_4界面的价带偏移（VBO）。VBO测量由两个不同的程序：一个间接的方法，涉及的核心水平的测量与XPS体价带（VB）光谱和直接的方法，涉及在界面处的XPS VB光谱的分析。间接法得到的VBO值为（−1.20 ± 0.14）eV，而直接法得到的值与此类似，为（−1.24 ± 0.06）eV，但不确定度较低。从测量的VBO值计算导带偏移（CBO）。这两个VBO的测量值使我们能够计算CBO，分别给出（−0.30 ± 0.14）eV和（−0.34 ± 0.06）eV。这些值表明，CBO具有类似悬崖的行为，这可能是CdS/CZTS太阳能电池中Voc限制的原因之一。
The valence band offset (VBO) at the interface CdS/Cu2ZnSnS4 was investigated by x-ray photoelectron spectroscopy (XPS). The VBO was measured by two different procedures: an indirect method involving the measurements of the core levels together with the XPS bulk valence band (VB) spectra and a direct method involving the analysis of XPS VB spectra at the interface. The indirect method resulted in a VBO value of (−1.20 ± 0.14) eV while the direct method returned a similar value of (−1.24 ± 0.06) eV but affected by a lower uncertainty. The conduction band offset (CBO) was calculated from the measured VBO values. These two measured values of the VBO allowed us to calculate the CBO, giving (−0.30 ± 0.14) eV and (−0.34 ± 0.06) eV, respectively. These values show that the CBO has a cliff-like behaviour which could be one of the reasons for the Voc limitation in the CdS/CZTS solar cells.