Influence of defect states on the performances of planar tin halide perovskite solar cells

Abstract

Although tin halide perovskite has shown excellent photoelectric performance, its efficiency of solar cell is low compared with that of lead halide. In order to enhance the efficiency of tin halide perovskite solar cell, a deep understanding of the role of the defects in the perovskite absorption layer and at the electron transport layer (ETL)/absorber or absorber/hole transport layer (HTL) interface is very necessary. In this work, the planar heterojunction-based CH3NH3SnI3 perovskite solar cells were simulated with the SCAPS-1D program. Simulation results revealed a great dependence of device efficiency on defect density and interface quality of the perovskite absorber. The defect density at the front interface is critical for high efficiency, and the polarity of the interface charge has a different impact on the device efficiency. Strikingly, an efficiency over 29% was obtained under the moderate simulation conditions.

Tin Halide Perovskites: Progress and Challenges

“…Similar improvement was reported for CsSnBr 3 Gupta et al The reduction of background carrier density and cation vacancies by using SnF 2 additive affects the WF and electronic band structure as revealed in CsSnBr 3 via UPS and XPS analyses . A careful variation of the concentration of such additive is important in this regard as it can also improve the affinity of the absorber layer for HTLs . The incorporation of superhalides such as BH 4 and AlH 4 can also enhance the oxidation resistance of Sn 2+ due to large electronic interactions between Sn 2+ and [BH 4 ] − /[AlH 4 ] − .…”

“…[103] A more in-depth kinetics study predicted improved performance in Sn-based devices provided reduction in defect density and recombination centers is ensured in the film. [104] To achieve this, a deep understanding of the factors responsible for the fascinating properties of Pb perovskites must be acquired. The effects of these factors on the Sn halide perovskites may be chemical composition dependent as evident, for example, in the wide range of carrier mobilities presented in Table 1.…”

“…[84] A careful variation of the concentration of such additive is important in this regard as it can also improve the affinity of the absorber layer for HTLs. [104] The incorporation of superhalides such as BH 4 and AlH 4 can also enhance the oxidation resistance of Sn 2+ due to large electronic interactions between Sn 2+ and [BH 4 ] − /[AlH 4 ] − . [229] Simulations have predicted that Sn halide perovskite based device could reach a PCE of 23.36%.…”

Perovskite Solar Cell design using Tin Halide and Cuprous Thiocyanate for Enhanced Efficiency

“…The range of QE 300 to 900 nm in which constant value of around 100% QE lies from 360-660 nm. The comparison between Referred designs [3,20,[24][25][26][27] with the simulated Proposed Design 1 is presented in Table III and the bar graph in figure 10. P1 represents the proposed simulated designs.…”

Study the effect of defects on the quantum efficiency of perovskite solar cells

“…The influence of the defects density Nt in the MAPbI3 layer on the quantum efficiency of perovskite solar cells was investigated by changing the defects density between 10 10 cm -3 and 10 18 cm -3 over a wavelength range of 300-800 nm. The defect level is set to 0.5 eV above the valance band [14], while all other parameters were kept constant such as capture cross-section in the absorber layer, which is set equals to 2×10 -15 cm 2 , and total density in both HTM and ETM interfaces that are set to 10 18 cm -2 . The results are presented in Figure (3).…”