Reaction path for formation of Cu2SnSe3 film by selenization of Cu–Sn precursor

Autor: Takashi Minemoto, Hikaru Uegaki, Daisuke Hironiwa, Kenta Aoyagi, Yuki Nukui, Jakapan Chatana, Kiichi Kosaka, Zeguo Tang
Rok vydání: 2015
Předmět:
Zdroj: Solar Energy Materials and Solar Cells. 143:311-318
ISSN: 0927-0248
DOI: 10.1016/j.solmat.2015.07.025
Popis: Reaction path for fabrication of Cu 2 SnSe 3 (CTSe) film by selenization of Cu–Sn precursor was investigated via in-situ X-ray diffraction (XRD) as well as glazing incident XRD (GIXRD) measurements. Cross-sectional scanning electron microscopy (SEM)-energy dispersive spectrometry (EDS) and transmission electron microscope (TEM) analyses revealed the element and phase distribution along the depth direction. Based on these results, a proposed growth model was concluded below: first, the Se atoms from evaporation source reacted with Cu and Sn atoms to produce Cu 2− x Se and SnSe 2 phases. Noticeably, resulting film presented bilayer feature with Cu 2− x Se located at the surface and SnSe 2 located at bottom. Second, CTSe phase formed at the interface of Cu 2− x Se and SnSe 2 as the increasing temperature. The Cu 2− x Se was depleted by Sn-related secondary phases when the Cu/Sn ratio was smaller than 1.72. The secondary phases of SnSe 2 and SnSe were coexisted with CTSe phase independent of Cu/Sn ratio in metallic precursor, which was attributed to the weak diffusion ability of Sn and Sn-related secondary phases in the CTSe film. The origins for high carrier concentration in CTSe films were ascribed to the Cu 2− x Se and intrinsic acceptor concentration and effective approach to reduce the value was explored. An attempt of solar cell with CTSe as absorber was performed and photocurrent of 9.9 mA/cm 2 was detected.
Databáze: OpenAIRE
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