Epitaxial and polycrystalline CuInS2 layers: Structural metastability and its influence on the photoluminescence

Tunable structural and optical properties of CuInS2 colloidal quantum dots as photovoltaic absorbers

“… 21–23 These along with the E 1 LO band at 337 cm −1 suggest a mixed phase attributed to off-stoichiometry 21,24 of CH and CA-type (copper–gold-type) tetragonal structures of a face centered cubic chalcogen lattice, differing in copper and indium sites. Since the CA-type phase is commonly associated with indium–copper anti-site defects 24,25 and the ternary phase diagram 17 of the Cu 2 S–In 2 S 3 system suggests that copper-rich CIS typically possesses copper–indium anti-site and indium vacancy defects, whilst indium-rich CIS possesses indium–copper anti-sites and copper vacancies , we could on the basis of the defect chemistry attribute reasons for the structural and optical properties of the QDs. Notably, both produce p-type CIS with acceptor energy states slightly above the valence band maximum and sulphur-deficient CIS typically has sulphur vacancies of n-type conductivity with donor energy states slightly below the conduction band minimum.…”

Effects of sulfurization and Cu/In ratio on the performance of the CuInS2solar cell

“…The peak at 1.4 eV was also assigned to a donoracceptor pair recombination in which generated electrons are trapped at V S and holes at either V In (In +3 ion vacancies) or Cu In [56]. The peak at 1.46 and 1.48 eV was reported to be donor-to-valence band transition and free-to-bound transition, respectively [57,58]. The peak between 1.51 and 1.53 eV belongs to the exciton emission of the CIS and dominates the luminescence in most of the sulfurized films.…”

“…In the case of CuInSe 2 film, an MoSe 2 layer having an appropriate thickness in the range of 100-200 nm provides adhesion and Ohmic contact at the CIS/Mo interface; otherwise, MoSe 2 layers having undesirable thicknesses result in film peel-off [55]. The peak at 1.46 and 1.48 eV was reported to be donor-to-valence band transition and free-to-bound transition, respectively [57,58]. Therefore, no peel-off was observed in the 450°C film; however, peel-off is more significant for the 500 and 550°C films.…”

Temperature‐dependent Raman investigation of CuInS2 with mixed phases of chalcopyrite and CuAu

“…The presence of the metastable CA phase is unavoidable in the CuInS 2 CH base structure 10. It has been observed that these two phases coexisted in epitaxial crystalline film 11, 12. The presence of the CA phase was reported to correlate with the S vacancy defect 13.…”