Power conversion efficiencies Perovskite 4 Solar power generation 4 Conversion efficiency 3 Open circuit voltage 3 Perovskite solar cells 3 Solar cells 3 Charge transfer 2 Efficiency 2 Energy gap 2 Hole mobility 2 Hole transporting 2 Lead compounds 2 Open-circuit voltages 2 Organic solar cells 2 Photovoltaic performance 2 1-methyl-3-propylimidazolium iodide 1 4-tert butylpyridine 1 4-tert-Butylpyridine 1 Boron-doped 1 Bulk heterojunction 1 Bulk heterojunction organic solar cells 1 Capacitance 1 Capacitance voltage 1 Carbon films 1 Carbon nitride 1 Carbon-based 1 Charge recombinations 1 Charge-separation 1 Coating techniques 1