Progress in charge transport layer materials for PSCs.

Perovskite	CTL (charge transport layer)	Methodology	Significance/improvements	References
MAPbI3	MoS2	Direct production of MoS2 nanosheets on ITO substrate	Enhanced interfacial charge transfer capabilities, stability, and overall performance	50
MAPbI3	MoS2	Used as HTL	Versatility of MoS2 as both ETL and HTL	52
MAPbI3	MoS2	Inverted p–i–n heterojunction planar PSC	Utilization of MoS2 as HTL	54
MAPbI3	Spiro-OMeTAD	Incorporation of benzoic acid	Accelerated oxidation and improved hole-transmitting properties	61
CsPbI2Br	Spiro-OMeTAD	Fluorinated spiro-OMeTAD without dopants	High PCE and exceptional longevity	62
MAPbI3	ZnO	Ultrasonic bath to produce ZnO nanoparticles in different solvents	Superior performance due to excellent MAPbI3 surface coverage and low defect density	66
MAPbI3	ZnSnO	Doping with silicon	Improved charge extraction and conduction capabilities	67
MAPbI3	TiO2	Lithium (Li) doping of TiO2	Enhanced conductivity and reduced solar power loss	73
MAPbI3	TiO2	Sol–gel production process with varying TiO2 concentrations	Enhanced efficiency of low-temperature solar panels	74
MAPbI3	TiO2	MgTiO3-coated TiO2 mesoporous scaffold layers	Improved photovoltaic performance and durability	75
MAPbI3	In2O3	Synthesis of stable In2O3 films at low temperatures	Enhanced electron extraction and charge transfer	78
MAPbI3	Cu2O/SiO2	RF magnetron sputtering	Enhanced PCE, reduced charge carrier recombination	79
MAPbI3	TiO2	Introduction of a thin m-TiO2 layer at the interface	Superior performance and low hysteresis coefficient	80
MAPbI3	MFIL	Multifunctional interface layer (MFIL) technique	Enhanced efficiency and durability	81
MAPbI3	ZnO	Production of well-ordered ZnO nanorods on FTO substrate	Improved electron transportation and increased contact area	82