Grain growth enhancing through preheating treatment of a sputtered stacked metallic precursor for Cu(In, Al)Se2 thin film solar cells application

Abstract

The influence of preheating treatment of a sputtered stacked metallic precursor on structural property of the CuInAl precursor and detailed structural, morphological and optical analyses as well as in the finally obtained Cu(In, Al)Se2 (CIAS) thin film solar cell device characterization are investigated systematically. These results indicate that this preheating process exhibits a strong beneficial impact on crystal growth and eventually produces a substantial improvement in photovoltaic properties. However, further increase of the preheating temperature, despite enhancing grain growth, clustering of grains loosely distribute on the surface of the CIAS thin film, forming a rather rough morphology. Thus, an accurate control of the preheating temperature during grain growth process may be necessary. Here, when optimizing the preheating temperature to 300 °C, the largest grain size and the best photovoltaic performance achieved. The findings provide an important insight into the understanding of fundamental research of current chalcopyrite solar cell application.