Order–Disorder Phenomena and Their Effects on Bandgap in ZnSnP2

详细信息    查看全文

• 作者：Shigeru Nakatsuka ; Yoshitaro Nose
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：January 19, 2017
• 年：2017
• 卷：121
• 期：2
• 页码：1040-1046
• 全文大小：445K
• ISSN：1932-7455

文摘

A ternary compound semiconductor ZnSnP<sub>2sub> has the order–disorder transition, where the ordered and disordered phases are chalcopyrite (I4̅2d, a = 5.651 Å, c = 2a) and sphalerite (F4̅3m, a = 5.651 Å), respectively. In this study, the quantitative relationship between bandgap and long-range order parameter η was investigated by analyzing ZnSnP<sub>2sub> bulk crystals obtained by various cooling rates in crystal growth. The Chipman and Warren method was used to evaluate the long-range order parameters from X-ray difffaction profiles. The results showed that the long-range order parameter η decreases from 0.94 to 0.54 with the increase in cooling rates, and the bandgap gradually reduced from 1.60 to 1.37 eV, corresponding to the η value. It was also demonstrated that bandgap tuning of ZnSnP<sub>2sub> was possible by controlling the long-range order parameter through annealing process. This study clarified the effects of the order–disorder phenomena on bandgap in a model material, ZnSnP<sub>2sub>, based on the evaluation of long-range order parameter, which is also a promising technique to tune the bandgap without composition control.