Efficiency improvement of CsSnI3 based heterojunction solar cells with P3HT HTL: A numerical simulation approach

•The PV performance of CsSnI3 solar cell investigated with and without HTL via SCAPS-1D.•Investigations five (P3HT, PEDOT:PSS, PTAA, MoO3, CFTS) HTL layers due to enhance PCE.•The maximum power conversion efficiency was found 17.04% with HTL (P3HT). Recently, lead free CsSnI3 based solar cells are gaining popularity among researchers due to their outstanding semiconducting characteristics. To improve the efficiency of the recently suggested ITO/ZnMgO/CsSnI3/P3HT/Au solar cell and examine the effects of the five HTL such as (P3HT, PEDOT:PSS, PTAA, MoO3, CFTS) and ZnMgO as ETL via SCAPS-1D on key performance indicators like PCE, FF, JSC and VOC is the main purpose of this works. The effects of thickness variation, carrier density, each layer’s interface defect, bulk defect density, operating temperature, and front and rear electrode placement have been studied. The PCE, VOC, JSC, and FF have shown 7.03 %, 0.32 V, 33.76 mA/cm2, and 62.50 %, respectively with reference structure’s (ITO/ZnMgO/CsSnI3/Au). The highest PCE, VOC, JSC, and FF is improved to 17.04 %, 0.67 V, 35.61 mA/cm2, and 71.39 %, respectively by adding P3HT layer as a HTL with proposed structures (ITO/ZnMgO/CsSnI3/P3HT/Au) then other four HTL (PEDOT:PSS, PTAA, MoO3, CFTS).