Wet-chemical synthesis of quaternary chalcopyrite Cu(In1−xAlx)Se2 nanocrystals by triethylenetetramine-assisted triethylene glycol solution process

Aluminum doping of CuInSe2 synthesized by solution process and its effect on structure, morphology, and bandgap tuning

“…The peak intensity gradually increases with increasing Al‐doping concentration, owing to the larger crystal grains. On the other hand, Al doping causes crystal diffraction symmetry breaking (discussed later), which will lead to weakening of the systematic extinction and the enhancement of peak intensity , moreover possibly showing a more effective aluminum solid solution in CIASe phase . Figure b presents the (112) diffraction peak of Cu(In 1− x Al x )Se 2 shifting toward the higher angle side with increasing Al‐doping concentration, which is similar to the reported literature .…”

“…According to the Bragg formula, the (112) peak shifts towards lower angles as temperature rises, which indicates that the plane interval distance increases during the heating process due to the unit‐cell thermal expansion. It is different from the results synthesized by hot‐injection process with organic solution , because the latter reaction degree varies with different synthesis temperature. The lattice constants of Cu(In,Al)Se 2 mostly increase as temperature rises, because higher temperature induces unit‐cell volume enlargement , as shown in Fig.…”

“…. For comparison, the theoretical E g is calculated by the following relation : …”

“…There are many reports on depositing Cu(In,Al)Se 2 thin films through high‐vacuum techniques, which needs high‐cost evaporation or sputtering equipments . Aiming to obtain a low‐cost, simple and less material wastage method to synthesize CuInSe 2 , recent studies have been taking solution‐based synthesis and have achieved that goal, such as electrodeposition , which needs a stable potential due to its great effect on material's morphology, composition, and bandgap, successive ionic layer adsorption and reaction , which should avoid the crosscontamination and improve the composition uniformity, air pressure hot‐injection process , which needs organic solution reaction at high temperature. In this paper, we present a wet chemical synthesis approach to Cu(In,Al)Se 2 absorber layers.…”

Structural, optical and electrical properties of Cu2FeSnSe4 and Cu(In,Al)Se2 thin films

“…As shown in Fig. 6, the most intense peak at 174 cm À 1 could be assigned to the A 1 mode which is the strongest mode generally observed in the Raman spectra of Cu-III-Se 2 system chalcopyrite compounds [28]. This mode results from the motion of the Se atom with the Cu and In (Al) atoms remaining at rest [29].…”