Consistently High Voc Values in p-i-n Type Perovskite Solar Cells Using Ni3+-Doped NiO Nanomesh as the Hole Transporting Layer

Ujwal K Thakur; Pawan Kumar; Sergey Gusarov; Alexander E Kobryn; Saralyn Riddell; Ankur Goswami; Kazi M Alam; Spencer Savela; Piyush Kar; Thomas Thundat; Alkiviathes Meldrum; Karthik Shankar

doi:10.1021/acsami.9b18197

Consistently High V_oc Values in p-i-n Type Perovskite Solar Cells Using Ni³⁺-Doped NiO Nanomesh as the Hole Transporting Layer

ACS Appl Mater Interfaces. 2020 Mar 11;12(10):11467-11478. doi: 10.1021/acsami.9b18197. Epub 2020 Feb 25.

Authors

Affiliations

¹ Department of Electrical and Computer Engineering, University of Alberta, 9211-116 St, Edmonton, Alberta T6G 1H9, Canada.
² Nanotechnology Research Centre, National Research Council Canada, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada.
³ Department of Materials Science and Engineering, Indian Institute of Technology, Hauz Khas, New Delhi 11016, India.
⁴ Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260-4200, United States.
⁵ Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada.

PMID: 31904215
DOI: 10.1021/acsami.9b18197

Abstract

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 hole transport layers (HTLs) struggle to generate open-circuit photovoltage values higher than 1 V. NiO HTLs have shown greater promise in achieving high V_oc values albeit inconsistently. In this report, a NiO nanomesh with Ni³⁺ defect grown by the hydrothermal method was used to obtain PSCs with V_oc values that consistently exceeded 1.10 V (champion V_oc = 1.14 V). A champion device photoconversion efficiency of 17.75% was observed. Density functional theory 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, field emission scanning electron microscopy, intensity-modulated photocurrent spectroscopy, intensity-modulated photovoltage spectroscopy, time-resolved photoluminescence, steady-state photoluminescence, and Kelvin probe force microscopy provided evidence of better film quality, enhanced charge transfer, and suppressed charge recombination in PSCs based on hydrothermally grown NiO nanostructures.

Keywords: KPFM; Ni3+-rich nickel oxide; charge transport and recombination; hole transporting layer; p-type metal oxides; quantum chemical computation; solvothermal synthesis; time-resolved photoluminescence.