Consistently high Voc values in p i n type perovskite solar cells using Ni3+ doped NiO nanomesh as the hole transporting layer.
Leading edge p i n type halide perovskite solar cells (PSCs) severely underperform n i p PSCs. p i n type PSCs that use PEDOT:PSS HTLs struggle to generate open circuit photovoltage (Voc) values higher than 1 V. NiO HTLs have shown greater promise in achieving high Voc values albeit inconsistently. In this report, a NiO nanomesh with Ni3+ defect grown by the hydrothermal method was used to obtain PSCs with Voc values that consistently exceeded 1.10 V (champion Voc 1.14 V) A champion device photoconversion efficiency (PCE) of 17.75% was observed. Density functional theory (DFT) modeling was used to understand the interfacial properties of the NiO/perovskite interface. The PCE of PSCs constructed using the Ni3+ doped NiO nanomesh HTL was ~34% higher than that of conventional compact NiO based perovskite solar cells. A suite of characterization techniques such as transmission electron microscopy (TEM) field emission scanning electron microscopy (FE SEM) intensity modulated photocurrent spectroscopy (IMPS) intensity modulated photovoltage spectroscopy (IMVS) time resolved photoluminescence (TRPL) steady state photoluminescence (PL) and Kelvin probe force microscopy (KPFM) provided evidence of better film quality, enhanced charge transfer and suppressed charge recombination in PSCs based on hydrothermally grown NiO nanostructures.
ACS applied materials interfaces