Formation of CuInSe₂ from Cu₂Se and In₂Se₃ compounds

Abstract

Chalcopyrite α‐CuInSe2 (α‐CIS) was prepared from mixed powders of Cu2Se and In2Se3 by annealing in the Se‐ and the non‐Se environments. The mechanically ground powders were in an overall amorphous state. The mechanical alloying produced Cu3Se2 and CuSe compounds. At relatively low temperature, Cu3Se2 decomposed, Cu2−xSe and CuSe formed. The reaction for the formation of α‐CuInSe2 occurred essentially at a temperature at ∼350 °C in both the Se‐ and the non‐Se environments. In the non‐Se environment, reactions occurred by a solid–solid reaction and a certain amount of Se were released from the mixed powder, resulting in poor crystalline α‐CuInSe2 powders. When annealed in the Se environment, low‐melting Se‐rich Cu‐Se compounds were produced during reaction. The reactions occurred by a liquid–solid reaction above 450 °C. Large‐grained and good crystalline quality of chalcopyrite CIS with near stoichiometric atomic ratio was obtained above 450 °C.

CuInSe2 Formation from CuSe/In2Se3 and Cu2Se/In2Se3 Powders: Reaction Kinetics and Mechanisms

“…For the samples calcined in air (non‐Se atmosphere), selenium would evaporate from the mixed powders at a temperature higher than 300°C, which led the Cu–Se compounds to be Se poor, such as Cu 2− x Se. Consequently, the reaction occurred mainly through the solid‐state reaction . Because of the dense network of the three‐dimensionally interconnected structure of γ‐In 2 Se 3 , the diffusion of Cu + in γ‐In 2 Se 3 is slow.…”

“…Nanosolar Company has announced that a CIGS solar cell with an efficiency of 14% can be prepared using a nonvacuum process using binary selenide nanoparticles as the precursors . The CIS formation reaction mechanism and kinetics from Cu 2 Se or CuSe and In 2 Se 3 powders have rarely been reported . In our previous study, the reaction mechanism and CIS formation kinetics using a solid‐state reaction from Cu 2 Se/In 2 Se 3 powders in a nonselenium atmosphere were investigated.…”

“…This indicated the reaction kinetics may be dominated by In 3+ diffusion . The reaction path and phase evolution during CIS synthesis strongly depends on the kinds of binary selenides used and the annealing atmosphere . Chen and Wang investigated CIS formation from Cu 2 Se and In 2 Se 3 compounds in Se and the non‐Se atmospheres.…”

“…The reaction path and phase evolution during CIS synthesis strongly depends on the kinds of binary selenides used and the annealing atmosphere . Chen and Wang investigated CIS formation from Cu 2 Se and In 2 Se 3 compounds in Se and the non‐Se atmospheres. They found that reactions occurred through solid–solid reaction in the non‐Se environment, but reactions occurred by a liquid–solid reaction due to the formation of low‐melting Se‐rich Cu–Se compounds during reaction in the Se environment.…”

Se-loss-induced CIS Thin Films in RTA Process after Co-sputtering Using CuSe2and InSe2Targets

“…An eco-friendly, simple and cheap method for fabricating CIS thin films without additional selenization / sulfurization process using Se-/ S-containing vapor needs to be developed, but few studies have been performed. Several efforts have been made to develop this method for preparing CIS thin films, such as Cu 2 Se + In 2 Se 3 by Chen and CuSe 2 +In in a previous study [8]. However, the loss of Se in thin films due to volatilization in heat treatment at higher temperatures for longer times could not be suppressed [9,10].…”