Minimization of carrier recombination in La₂NiMnO₆ double perovskite solar cells by optimizing defects and band offsets

Abstract

In the present work, an extensive study has been carried out on the parameters that govern the non-radiative recombination losses associated with the absorber double perovskite material. Four different device configurations have been proposed by incorporating different electron transport layers (ETL) namely tungsten disulfide (WS2), tungsten trioxide (WO3), zinc selenide (ZnSe), and strontium titanate (STO) with La2NiMnO6 (LNMO) double perovskite material as an active layer and cuprous oxide (Cu2O) as a hole transport layer (HTL). In this investigation, the role of band offsets in the collection, transportation, and recombination of charge carriers has been examined in detail. Further, the impact of thickness and the defect positions i.e. shallow defects and deep defects on the photovoltaic (PV) parameters of the cells has been thoroughly elucidated. For the proper collection of charge carriers, the ideal barrier height between HTL and back contact (C, Ni, Ag, and Au) at various valence band maximum (VBM) levels has also been investigated. Interestingly, the results of the present simulation reveal that the WS2-based device with configuration FTO/WS2/LNMO/Cu2O/Au shows the highest PCE of 24.08% after optimization. The findings and interpretation of this work demonstrate that La2NiMnO6 an eco-friendly and non-toxic material can be used to produce high-efficiency perovskite devices.

Insight into the Microband Offset and Charge Transport Layer’s Suitability for an Efficient Inverted Perovskite Solar Cell: A Case Study for Tin-Based B-γ-CsSnI3

“…A cliff occurs at the ETL/perovskite interface when the perovskite layer’s CBM is greater than the ETL’s CBM; this allows electrons to flow more freely toward the metal contacts and is called negative CBO. The alignment of the valence band maxima (VBM) of the perovskite and HTL layers, as well as a substantial offset between their conduction bands, are also necessary for the separation of holes in the perovskite layer and HTL. , …”

“…The alignment of the valence band maxima (VBM) of the perovskite and HTL layers, as well as a substantial offset between their conduction bands, are also necessary for the separation of holes in the perovskite layer and HTL. 68,71 Figure 5a,b shows the change in performance parameters with different values of the VBO for various HTLs, for C 60 , PCBM, and PDINO ETLs. V OC increases slightly with an increase in VBO from 0.15 to 0.2 eV, followed by a sharp decrease until VBO reaches 0.35 eV.…”