The Interplay between Dopant and the Surface Structure of an Electron Transport Layer in N719 Solid State Dye-Sensitized Solar Cells: An Analysis of Aluminum-doped Faceted TiO2 with Mg-CuCrO2 Transport Channels Using the SCAPS-1D Framework

Abstract

Solid state dye-sensitized solar cells (ssDSSCs) are attracting increasing attention due to their affordable manufacturing, adaptability to lightweight and flexible applications. This present work utilized solar capacitance simulation software to examine the performance of ssDSSCs with both Al3+ doped and undoped TiO2 electron transport layer (ETL). The pure titanium dioxide based device gave an open circuit voltage Voc, short circuit current density Jsc, fill factor FF and power conversion efficiency PCE 0.95 V, 15.16 mA cm−2, 64.49% and 9.30%, respectively, while the aluminium doped TiO2 presents 0.87 V, 18.53 mA cm−2, 68.73% and 11.09% as Voc, Jsc, FF and PCE, respectively. This shows that Al3+ doped ETL was more promising. The effects of using different hole transport layers (HTLs) were studied. Delafossite (Mg-CuCrO2) was found to be the most potential HTL to dramatically improve device performance with Voc 0.87 V, Jsc 19.16 mA cm−2, FF 68.52% and PCE 11.44%. The performance of the fluorine-doped tin oxide (FTO)/Al-TiO2/N719/Mg-CuCrO2/C device was optimized by varying the ETL thickness and doping concentration, dye thickness and defect density, HTL thickness and doping concentration to obtain 0.16 μm, 1020 cm−3, 0.9 μm, 1013 cm−2, 0.6 and 1022 cm−3 as optimal values, respectively. This showed a noticeable performance with optimized PCE 23.75%, supported with FF 84.98%, Jsc 24.12 mA cm−2 and Voc 1.16 V. The effect of series and shunt resistances, temperature, metal work function, capacitance and Mott-Schottky plot were evaluated and found to affect the optimized device.