Lee, Hanseul Jung, Hye Ri Pak, Sooyeon Kwon, Namhee Kim, Sang Hoon Na, Junhong Ko, Seoyeon Yoon, Seokhyun Kim, Won Mok Jeong, Jeung-hyun Kim, Donghwan Park, Soohyung Kim, Gee Yeong 2025-09-22T02:00:39Z 2025-09-22T02:00:39Z 2025-09-16 2025-09 1944-8244 https://pubs.kist.re.kr/handle/201004/153200 NiO x is a p-type semiconductor widely used as a hole transport material in perovskite solar cells (PSCs), yet the impact of fabrication methods on its interfacial properties and the underlying mechanisms remains unclear. This study investigates how the fabrication process-nanoparticle precursor (NP NiO x ) and sputtering deposition (SP NiO x )-and interfacial space charge effects influence charge transport and device performance in NiO x /perovskite systems. SP NiO x exhibits a higher Ni3+/Ni2+ ratio and greater conductivity but induces significant hole depletion and band bending at the interface, leading to reduced open-circuit voltage and efficiency. In contrast, NP NiO x shows weaker hole depletion and a negligible hole barrier and enhances hole extraction, achieving a higher efficiency. The improved interfacial behavior of NP NiO x is attributed to the presence of carbon ligands, which mitigate interfacial recombination. These findings highlight the critical role of interfacial engineering in optimizing charge transport and performance in PSCs, providing valuable insights into the design of efficient hole transport layers (HTLs). English American Chemical Society Unveiling NiOx /Perovskite Interfaces: Charge Transport and Device Performance in Perovskite Solar Cells Article 10.1021/acsami.5c13836 1 ACS Applied Materials & Interfaces, v.17, no.37, pp.52263 - 52275 ACS Applied Materials & Interfaces 17 37 52263 52275 N scie scopus 001565480600001 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article NICKEL-OXIDE OXYGEN METAL EXTRACTION XPS EFFICIENT SURFACES LAYER FILMS NI3+ inverted perovskite solar cell nickel oxide space charge effect interface effect hole depletion charge transport