Comparative study of the luminescence and intrinsic point defects in the kesterite Cu2ZnSnS4and chalcopyrite Cu(In,Ga)Se2

Abstract

The kesterite Cu 2 ZnSnS 4 (CZTS) is attracting considerable interest because first principles calculations predict that its electronic properties must be similar to their associated chalcopyrite

Phase-transition-driven growth of compound semiconductor crystals from ordered metastable nanorods

“…The PL peak position blue shifts by 10-20 meV/decade with increasing excitation power (inset of Fig. 5b), indicating strong compensation, which has been found to be a necessary prerequisite for good solar cell performance in chalcopyrite as well as kesterite-based thin film solar cells [45][46][47]. The observed PL bands in CZTS annealed samples can be attributed to quasi donor acceptor recombination [10].…”

Luminescence of Cu2ZnSnS4 polycrystals described by the fluctuating potential model

“…4,20 This model has also been shown to be appropriate for describing luminescence in Cu(InGa)Se 2 . 44 In heavily doped semiconductors, discrete energy levels associated with shallow impurities, both donor and acceptor, broaden resulting in the formation of impurity bands which ultimately merge with the conduction and valence band density of states into the fundamental energy gap.…”

“…Some ambiguity exists regarding PL of CZTS as previous luminescence studies of CZTS single crystals have claimed that the observed luminescence is due to impurities giving rise to donor acceptor pair (DAP) emission. 18,19 More recent studies have proposed a model of fluctuating potentials 4,20 initially developed by Levanyuk and Osipov. 21 Hall measurements have shown that the CZTS system has high doping levels, around 2 Â 10 20 cm À3 , with high levels of compensation predominantly from native defects.…”

“…It belongs to the I 2 -II-IV-VI 4 semiconductor system, 5,[8][9][10][11] and is a member of the adamantine family. 12 CZTS has been identified as having a direct fundamental energy gap, with a high absorption coefficient, which is close to the maximum of the solar spectrum.…”

“…2 Predictions based on the availability of constituent elements confirm that CdTe and CIGS technologies can contribute to energy supply in the hundreds of GW range. 3,4 To enable greater deployment of terrestrial PV at the TW level will require: (1) continued, and significant, cost reduction of PV modules; and (2) the ability to manufacture PV devices from sustainable materials. 5 These factors and recognition of the importance of environmental factors including cost and availability of metals and toxicity of PV component elements 6,7 have all led to a significant focus on new sustainable materials for PV devices.…”