The fabrication of the novel semiconducting material for solar cells which does not use a rare metal

采用垂直布里奇曼法生长了四元半导体Cu2ZnSnSe4和Cu2ZnSnS4晶体。光吸收测量表明，Cu2ZnSnS4和Cu2ZnSnS4都是直接禁带半导体，在10K时的禁带宽度分别为1.12和1.48 eV。热反射光谱在E0-E6临界点(Cp‘s)的能量处显示出不同的结构。根据第一性原理能带结构计算，这些CP被分配给布里渊区中的特定点。

The quaternary semiconductor Cu2ZnSnSe4 and Cu2ZnSnS4 crystals were grown by the vertical Bridgman method. Optical absorption measurements indicate that both Cu2ZnSnSe4 and Cu2ZnSnS4 are direct-gap semiconductors, and having the band gap energies of 1.12 and 1.48 eV at 10 K, respectively. The thermoreflectance spectra reveal distinct structures at energies of the E0-E6 critical points (CP's). From the first-principle band-structure calculations, these CP's are assigned to specific points in the Brillouin zone.