## 1 Introduction
In addition, p-type inorganic semiconductor materials that can serve as a hole transport layer (HTL) include MoO\({}_{3}\), CuI, NiO\({}_{x}\) and Cu\({}_{2}\)O [31; 32; 33]. MoO\({}_{3}\) has a wide bandgap, typically around 3.0 eV, which contributes to its transparency in the visible part of the spectrum [34]. This makes it useful in applications requiring transparent conducting layers, as well as in optoelectronic devices where light absorption or transmission is critical. Also, MoO\({}_{3}\) has a high work function, which makes it an excellent hole-injection layer in organic electronic devices [35]. This property facilitates the efficient transfer of holes from the anode to the organic layer in organic-emitting diodes (OLEDs) and organic photovoltaics (OPVs). Copper Iodide (CuI) is another p-type inorganic semiconductor material known for its distinctive properties that make it suitable for a range of electronic and optoelectronic applications [36]. CuI has a direct bandgap that is typically reported to be around 3.1 eV, making it transparent to visible light [37]. One of the significant advantages of CuI is its relatively high hole mobility compared to other p-type semiconductors [38]. CuI is chemically stable under a wide range of conditions and can be easily doped with various elements to fine-tune its electrical and optical properties [39]. P-type NiO\({}_{x}\) demonstrates a significant bandgap (greater than 3.5 eV) coupled with exceptional transparency within the visible spectrum [40]. This characteristic effectively reduces losses, including charge recombination, improves charge transport, and ensures ideal energy level alignment with diverse photoactive absorbers, attributed to its adequate conductivity and chemical stability [41; 42; 43]. These properties have led to extensive research on using these materials as hole injection layers or hole transfer layers in Quantum-Organic Light Emitting Diodes (QLED) device structures [44; 45]. In this paper, Cu\({}_{2}\)O was selected as the hole transport layer (HTL) material. Because Cu\({}_{2}\)O has a low bandgap energy of 1.8-2.5 eV, the efficient conversion of light into electrical energy is possible, and it has a high hole mobility, enabling the photovoltaic solar cell efficiency to be improved [46; 47]. Furthermore, Cu\({}_{2}\)O is a stable material and does not undergo significant changes in its electronic properties, even under harsh conditions, and it is a non-toxic and environmentally friendly material, making it a desirable choice for applications in the fields of energy and environment [48; 49]. Therefore, in this study,TiO\({}_{2}\) and Cu\({}_{2}\)O were selected as the ETL and HTL materials, respectively, based on these excellent characteristics and the band alignment of the energy band diagram. In summary, this study optimized the power conversion efficiency (_PCE_) of perovskite solar cells using TiO\({}_{2}\) as an Electron Transport Layer (ETL), MAPbI\({}_{3}\) as an absorber layer, and Cu\({}_{2}\)O as a Hole Transport Layer (HTL), respectively. We analyzed the effects of the following parameters on the power conversion efficiency (_PCE_) of perovskite solar cells (PSCs) through parameters optimization via the SCAPS-1D simulation tool [50; 51]: HTL thickness, perovskite absorber layer (PAL) thickness, ETL thickness, the defect density in the perovskite absorber layer (PAL), the defect density at the interface between the absorber and electron transport layers (ETLs), and that between the absorber and hole transport layers (HTLs). Hence, herein, each key factor on _PCE_ was optimized through a SCAPS-1D simulation, and the effects of each factor on the _PCE_ were clarified.