Solution based synthesis of Cu(In,Ga)Se₂ microcrystals and thin films

Abstract

Herein, for the first time, we report the synthesis of quaternary Cu(In,Ga)Se2 microcrystals (CIGSe MCs) using a facile and economical one-pot heating-up method.

Unveiling the impact of Cu content on the physical properties and photovoltaic performance of solution‐processed Cu(In,Ga)Se2solar cell absorber

“…From both planar and cross‐sectional images, it is possible to observe the increment in the grain size at CGI value of 0.70, 0.75, and 0.80, whereas nearly a similar pattern was noticed when CGI value was between 0.85 and 0.97 which might be due to the stacking nature of flakes. A significant change may not be visible when the same thickness of flakes stacks together as noticed by other researchers 23,44 …”

“…Based on the morphological results from Figure 2, we believe that the observed nanosized irregular shaped crystals at CGI value of 0.70, 0.75, and 0.80 might be due to the nucleation of smaller size CuSe seeds with an irregular shape. Because we attained the microsized hexagonal flake‐like shape of CIGSe crystals via hexagonal‐shaped CuSe nuclei with a size of ~0.20 μm 23 . Therefore, we consider a similar mechanism that might have happened at the CGI value of 0.85, 0.90, and 0.97 as the submicron and microsized hexagonal shape of crystals was obtained.…”

“…Therefore, CIGSe powder was dispersed in ethanol to formulate the ink, which was then coated as thin films by the drop‐casting method. In our previous reports, we demonstrated the successful transformation of CIGSe powder into thin films as perceived structural and compositional results of thin films are very similar to the powder 23 . Hence, we focused on the morphological, electrical and photoresponse properties of thin films in this work.…”

“…In this work, one‐pot heating‐up method 23 was used to synthesize CuIn 0.70 Ga 0.30 Se 2 with different Cu/Ga + In (CGI) values as described below. For the synthesis of Cu 0.70 In 0.70 Ga 0.30 Se 2 , 0.7 mmol of CuCl, 0.7 mmol of InCl 3 , 0.3 mmol of GaCl 3 and 2 mmol of elemental selenium were mixed into 10 mL of OLA at room temperature (RT) which was then heated to 250°C under a nitrogen atmosphere and the reaction was maintained at this temperature for 2 hours.…”

“…Herein, we intend to use non‐vacuum (solution) process for the synthesis of CIGSe powder at different CGI values which is then subsequently coated as thin films. The solution approach is an economical, facile process, showed high‐efficiency in material utilization nearly 100% and applicable for large area/scale with control over composition 23,24 . To the best of our knowledge, there are no reports available for CIGSe at different CGI values by solution process.…”