RF sputtered GZO thin films for enhancing electron transport in perovskite solar cells

Aiming to enhance the properties of gallium doped zinc oxide (GZO) for considering it as a promising electron transport layer (ETL) in perovskite solar cells (PSCs), GZO thin films were sputtered using radio frequency (RF) magnetron sputtering under different Ar gas flow from 2 sccm to 5 sccm. Then the variations of morphological, structural, optical and electrical properties of the GZO thin films were studied thoroughly. The sputtered GZO films showed polycrystallinity having a hexagonal wurtzite-type crystal structure with a preferred crystal orientation in the direction of (0 0 2). In terms of morphological analysis, EDX confirmed the presence of Ga and FESEM analysis revealed that the thickness and grain size of deposited films gradually increase with the increment of Ar flow. Further, the film deposited at 3 sccm showed the lowest electrical resistivity of 1.09 x 10-02 omega-cm and achieved the highest carrier concentration of 1.586 x 1019 cm -3. All the GZO films showed optical transmittances between -80 % and -90 %. Finally, the simulation study validated the use of sputtered GZO as ETL in PSCs. This study provides a significant path for the researchers to optimize the RF-sputtered GZO films by varying the Ar gas flow rate for confirming their use as promising ETL in PSCs.