## 1 Introduction  
Hybrid organic-inorganic perovskite materials exhibit the advantages of easy fabrication, a large absorption coefficient, an adjustable energy band gap, high carrier mobility, and a long charge carrier diffusion length [1; 2; 3; 4]. Metal halide-based perovskite solar cells (PSCs) have aimed for a better power conversion efficiency (PCE) for the next generationof photovoltaics [5; 6; 7].It should be pointed out that even if a lot of effort has been spent on the development of novel alternative solar cells like quantum dot solar cells [8] and single-material organic solar cells [9], perovskite-like solar cells are the most promising type of photovoltaic devices. To comprehend the green renewable energy demand, not only the cost-effectiveness of photovoltaic systems but also the expansion of its installation locations should be carefully established. Since the utility market facility has to regulate its growth rate, building-integrated photovoltaics is a potential candidate to solve such green renewable energy expectation. In recent years, organic-inorganic hybrid substances, the remarkably dictated perovskite family, has shown great distinction for field-effect solar cells [10; 11]. Lately, the PCE of lead halide perovskite (CH\({}_{3}\)NH\({}_{3}\)PbX\({}_{3}\), X = Cl, Br, I)-based thin-film photovoltaic devices reached 22% [12; 13; 14; 15; 16]. The organic metal halide material has excellent performance for solarphoton harvesting due to its low energy band gap and large excitation diffusion length [17; 18]. The optical energy band gap of organic metal perovskite (CH\({}_{3}\)NH\({}_{3}\)PbI\({}_{3}\); MAPbI\({}_{3}\)) is \(\sim\)1.56 eV. Consequently, this material benefits from efficient carrier generation and transportation to electrodes that can harvest sunlight radiation fromthe ultra-violet to infrared region. The diffusion length is more than one micrometer in the mixed halide perovskite [18]. [PERSON] et al. have investigated an organometal halide perovskite solar cell with a mesoporous TiO\({}_{2}\). They used a CH\({}_{3}\)NH\({}_{3}\)PbI\({}_{3}\) and CH\({}_{3}\)NH\({}_{3}\)PbBr\({}_{3}\) nano-crystal material as absorbers, achieving an efficiency of 3.8% [19]. In 2012, [PERSON] and [PERSON] et al. researched a complete solid-state perovskite solar cell within FTO (fluorine-tin-oxide)/mesoporous TiO\({}_{2}\)/perovskite/2,2\({}^{\prime}\),7,7\({}^{\prime}\)-tetrakis(N,N-di-p-methoxyphenylyl-amino),9\({}^{\prime}\)spirobifluorene(SpiroOMeTAD)/gold structure, achieving an efficiency of 9% [20]. One year later, the first unique inverted planar composition nano-structure of a perovskite solar cell was announced and a similar nano-structure device was used in other organic perovskite solar cells [21]. This inverted nano-structure was fabricated on ITO (indium-tin-oxide)/poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS)/perovskite/(6,6)phenyl-C61-butyric-acid-methylester(PCBM)/silver, and PEDOT:PSS was used as the hole-transporting material(HTM). However, the traditional hole-transporting material of PEDOT:PSS is acidic, which can erode ITO and decrease the reliability of the perovskite solar cells [22; 23]. Further investigations into the efficiency are still required for solar cells using other thin film materials, such as CdTe and CuIn\({}_{1-x}\)Ga\({}_{x}\)Se\({}_{2}\)[24]. Lately, [PERSON] et al. evaluateda film interface-related reducing mechanism and improved the PCE stability of small-area solar cells [25]. Photovoltaic technology has showncontinuous improvement, withenhanced device stability and improved cell durability. The future prospects areindeed obvious for the renewable energy realm [26]. The stability requirements can be established by solar cell devices with a unique combination of material composition and device structure, toward cell efficiency, scalability, and durability [27]. Usually, FTO is used to replace ITO asthe transparent conducting oxide (TCO).