Structural and electric properties of CuSbS2 compound semiconductor bulk crystals

Copper antimony disulfide (CuSbS2) is a promising candidate for solar absorber material owing to its high photoabsorption property and earthabundant constituent elements. In this study, we fabricated CuSbS2 crystals of various nonstoichiometric compositions and investigated their optical and electric properties for their applications in photovoltaic devices. Band gap energies of CuSbS2 crystals thus- obtained were almost constant (ca. 1.5 eV) irrespective of their compositions. Hall-resistivity measurements exhibited that a CuSbS2 crystal with the compositional formula of 1.03/1.00/1.86 showed the best properties among the samples prepared in this study: the resistivity, hole concentration, and mobility of the sample were 1.4 Omega cm, 6.0 x 10(16) cm(-3), and 7.4 cm(2)V(-1)s(-1), respectively. Although further optimization would be expected, the obtained properties are suitable for an absorber of photovoltaics. (C) 2018 The Japan Society of Applied Physics