Synthesis and characterization of semitransparent Sb2S3 based solar cells

In these last years the need of a sustainable, renewable, and cost-efficient energy source is becoming one of the most important topics in the materials science community. In particular, the research is focusing on cheap, light, and flexible new material, with the aim of developing flexible or semitransparent device that can be integrated in buildings and architectonic elements (the so-called building integrated photovoltaics) guaranteeing good performances to complement building powering. One of the most promising materials are metal chalcogenides. Antimony sulfide, in particular, seems to be very promising due to its excellent photoelectronic properties. The main issue of antimony sulfide is that its strong anisotropy requires a proper control of the crystal orientation. With the aim of developing efficient and semitransparent thin film solar cells, the fabrication of the Sb2S3 with the chemical bath deposition was optimized and the use of two different electron transport layers (ETL) (TiO2 and CdS) was compared. Titania resulted to be the best choice as ETL for efficient and semitransparent solar cell; the increase of the open circuit voltage for CdS as ETL was not sufficient to compensate its parasitic light absorption. In order to have a better crystal orientation of antimony sulfide and then a higher mobility of charge carriers, spin coating deposition was also evaluated but the power conversion efficiency (PCE) resulted to be lower (PCE = 1.18 %) than the one for CBD devices (PCE = 1.79 %). Finally, the semitransparent solar cell was further optimized by improving the counter electrode thickness, reaching a maximum PCE of 0.51 %.