Numerical Simulation of High-Performance CsPbI3/FAPbI3 Heterojunction Perovskite Solar Cells

Abstract

To broaden the absorption spectrum of cells, enhance the cell stability, and avoid high costs, a novel perovskite solar cell (PSC) with the structure of fluorine-doped tin oxide (FTO)/ZnO/CsPbI3/FAPbI3/CuSCN/Au is designed using the solar cell capacitance simulator (SCAPS) software. The simulation results indicate that the CsPbI3/FAPbI3 heterojunction PSC has higher quantum efficiency (QE) characteristics than the single-junction CsPbI3-based PSC, and it outputs a higher short-circuit current density (Jsc) and power conversion efficiency (PCE). In order to optimize the device performance, several critical device parameters, including the thickness and defect density of both the CsPbI3 and FAPbI3 layers, the work function of the contact electrodes, and the operating temperature are systematically investigated. Through the optimum analysis, the thicknesses of CsPbI3 and FAPbI3 are optimized to be 100 and 700 nm, respectively, so that the cell could absorb photons more sufficiently without an excessively high recombination rate, and the cell achieved the highest PCE. The defect densities of CsPbI3 and FAPbI3 are set to 1012 cm−3 to effectively avoid the excessive carrier recombination centering on the cell to increase the carrier lifetime. Additionally, we found that when the work function of the metal back electrode is greater than 4.8 eV and FTO with a work function of 4.4 eV is selected as the front electrode, the excessively high Schottky barrier could be avoided and the collection of photogenerated carriers could be promoted. In addition, the operating temperature is proportional to the carrier recombination rate, and an excessively high temperature could inhibit Voc. After implementing the optimized parameters, the cell performance of the studied solar cell was improved. Its PCE reaches 28.75%, which is higher than most of existing solar cells. Moreover, the open circuit voltage (Voc), Jsc, and PCE are increased by 17%, 9.5%, and 25.1%, respectively. The results of this paper provide a methodology and approach for the construction of high-efficiency heterojunction PSCs.

Improved Performance of Lead‐Free Perovskite Solar Cells Based on Multi‐Absorber MASnI3/CsGeI3 Heterojunction by Device Simulation

“…It is known that the increase of temperature will increase the thermal energy of carriers, leading to soaring of recombination rates and thus the loss of V oc . [ 18 ] Therefore, an enhanced V bi of the p‐p + Sn/Ge heterojunction is expected to induce a stronger electric field that allows oriented charge movement, reducing their recombination before being collected by the electrodes, and consequently, minimizes this energy loss. [ 25a,32 ] These results demonstrate the superiority and practical potential of the well‐designed multi‐absorber PSCs.…”

“…In addition, the increased thickness of less conducting MASnI 3 absorber would result in increased series resistance of the whole device and the internal power consumption. [18,26] Thus the FF is also reduced. Therefore, a moderate MASnI 3 thickness of ≈100 nm would contribute to an overall higher PCE as shown in Figure 3d.…”

“…[5] Despite the rapid growth and a decade of intense research, there One effective method to improve the single-junction PSCs is constructing heterojunction structures in which series of perovskite materials with various light absorbing regions are stacked on top of each other. [17] Such structures can extract a wider energy range from solar spectrum to enhance the PCE [18] and have been widely applied in lead-based PSCs, e.g., p-n junction [19] or tandem PSCs [20] which break the singlejunction Shockley-Queisser limit. In this work, we propose a novel p-p + MASnI 3 /CsGeI 3 heterojunction structure to improve the performance of CsGeI 3 based PSCs.…”

Numerical Analysis of Stable (FAPbI3)0.85(MAPbBr3)0.15-Based Perovskite Solar Cell with TiO2/ZnO Double Electron Layer

“…Moreover, the solution-based preparation of perovskite thin films is rather cost-effective as it only requires low temperatures and small amounts of materials [6]. Since the organic-inorganic hybrid PSCs were first proposed in 2009 [7], the power conversion efficiency (PCE) values of single-junction PSCs have increased from 3.8% to 25.7% [8][9][10][11][12], which is comparable to that of C-Si solar cells. However, there is still a certain gap between the current PCE level and the theoretical limit of PCE of PSCs [2] due to the nonradiative recombination of carriers caused by the point defects of the materials, light emitting, or the heating effect [13].…”

Optimization of Inverted All-Inorganic CsPbI3 and CsPbI2Br Perovskite Solar Cells by SCAPS-1D Simulation

“…All-inorganic CsPbI x Br 3−x perovskite (with x between 0 and 3) have a band gap ranging from 1.73 eV (CsPbI 3 ) to 2.31 eV (CsPbBr 3 ) [18]. CsPbI 3 has the most suitable band gap to fabricate high-efficiency PSCs, being therefore an ideal material to prepare tandem devices combined with either silicon or low band gap perovskite solar cells [19,20]. Although CsPbBr 3 exhibits a great phase stability, the large band gap limits its efficiency [21].…”