Effect of Various Electron and Hole Transport Layers on the Performance of CsPbI₃-Based Perovskite Solar Cells: A Numerical Investigation in DFT, SCAPS-1D, and wxAMPS Frameworks

Abstract

CsPbI 3 has recently received tremendous attention as a possible absorber of perovskite solar cells (PSCs). However, CsPbI 3 -based PSCs have yet to achieve the high performance of the hybrid PSCs. In this work, we performed a density functional theory (DFT) study using the Cambridge Serial Total Energy Package (CASTEP) code for the cubic CsPbI 3 absorber to compare and evaluate its structural, electronic, and optical properties. The calculated electronic band gap ( E g ) using the GGA-PBE approach of CASTEP was 1.483 eV for this CsPbI 3 absorber. Moreover, the computed density of states (DOS) exhibited the dominant contribution from the Pb-5d orbital, and most charges also accumulated for the Pb atom as seen from the electronic charge density map. Fermi surface calculation showed multiband character, and optical properties were computed to investigate the optical response of CsPbI 3 . Furthermore, we used IGZO, SnO 2 , WS 2 , CeO 2 , PCBM, TiO 2 , ZnO, and C 60 as the electron transport layers (ETLs) and Cu 2 O, CuSCN, CuSbS 2 , Spiro-MeOTAD, V 2 O 5 , CBTS, CFTS, P3HT, PEDOT:PSS, NiO, CuO, and CuI as the hole transport layers (HTLs) to identify the best HTL/CsPbI 3 /ETL combinations using the SCAPS-1D solar cell simulation software. Among 96 device structures, the best-optimized device structure, ITO/TiO 2 /CsPbI 3 /CBTS/Au, was identified, which exhibited an efficiency of 17.9%. The effect of the absorber and ETL thickness, series resistance, shunt resistance, and operating temperature was also evaluated for the six best devices along with their corresponding generation rate, recombination rate, capacitance–voltage, current density–voltage, and quantum efficiency characteristics. The obtained results from SCAPS-1D were also compared with wxAMPS simulation results.

Combined DFT, SCAPS-1D, and wxAMPS frameworks for design optimization of efficient Cs2BiAgI6-based perovskite solar cells with different charge transport layers

“…An efficient creation and separation mechanisms of electron-hole pairs are made possible by the greater depletion width, which raises the Electron mobility, cell's quantum efficiency. 14 Cs 2 BiAgI 6 captures photons due to double heterostructure it ensures the charge and photon connement and both sides of highly doped ETL and HTL work as an ohmic contact. During the study SCAPS-1D, the soware helps us to investigate the performance of various structures of double PSCs.…”

“…52,53 In our recent study, we reported that CsPbI 3 absorber layer-based device with CBTS as HTL exhibited PCE of 16.71%, 17.90%, 17.86%, 14.47%, 17.76%, 17.82% with PCBM, TiO 2 , ZnO, C 60 , IGZO, WS 2 ETL respectively. 14 Another study demonstrates that using SnO 2 as ETL and CuSCN as HTL with MAPbI 3 absorber demonstrated a high PCE of 27%. 52 Therefore, more research needs to be done to investigate the device performance of PSCs for different ETL, HTL, and back contact metals with lead-free perovskite absorber layers, to outperform Shockley Queisser's (SQ) efficiency limit for a single solar cell.…”

“…The electronic properties such as band gap and band structure, density of states (DOS), and charge density distribution are crucial for the investigation of the electronic contribution of different elements in perovskites and other structural compounds. 14,54,55 The state of a material system can be properly understood by exploring its physical properties. It can also identify a material's possible practical applications.…”

“…[11][12][13] Despite the outstanding performance of PSCs, two major challenges prevent them from commercial applications like the use of the toxic material lead and organic cations, which have a volatile and hygroscopic nature. 14 Organic-inorganic hybrid PSCs are chemically unstable when exposed to oxygen, moisture, and high temperatures because the organic cations are hygroscopic and volatile. 15 On the other hand, lead-based halide perovskite is a highly toxic and hazardous material that can cause severe health and environmental issues.…”

“…Nowadays, researchers have been performing theoretical works to explore the physical properties of materials of interest via the density functional theory (DFT). According to reports, 14,[56][57][58] several halide perovskite materials exhibit intriguing physical characteristics including structural, electrical, optical, and mechanical characteristics that make them potential candidates for optoelectronic and photovoltaic operations. Recently, Hadi et al 59 have investigated the structural, electronic, optical, and mechanical properties of lead-free cubic double perovskite-type Cs 2 AgBiBr 6 using the DFT method.…”