Hole Trapping by Iodine Interstitial Defects Decreases Free Carrier Losses in Perovskite Solar Cells: A Time-Domain Ab Initio Study

Abstract

We present a time-domain ab initio study of electron−hole recombination in pristine MAPbI 3 , and compare it to the trap mediated recombination in MAPbI 3 with the iodine interstitial defect. Nonadiabatic molecular dynamics combined with time-domain density functional theory show that the iodine interstitial defect creates a subgap state capable of trapping both electrons and holes. Hole trapping occurs much faster than electron trapping or electron−hole recombination. The trapped hole survives for hundreds of nanoseconds, because, rather surprisingly, recombination of electrons with the trapped hole takes several times longer than recombination of electrons with holes in the valence band. Because the hole trap is relatively shallow, the hole can escape into the valence band prior to recombining with the electron. The differences are rationalized by variation in nonadiabatic electron−phonon couplings, phonon-induced pure-dephasing times and electronic energy gaps. The time-domain atomistic simulations contribute to understanding of the experimentally known defect-tolerance of perovskite solar cells, which is of great importance to the solar cell performance.

Passivating Detrimental DX Centers in CH3NH3PbI3 for Reducing Nonradiative Recombination and Elongating Carrier Lifetime

“…2020, 32,1906115 www.advmat.de www.advancedsciencenews.com whereas its role on charge carrier trapping and recombination is less explored. [62][63][64] Although the bandgap can be correctly produced by combining SOC with hybrid functionals or GW calculations, [61] this is too expensive for NAMD, which involves thousands of repeated electronic structure calculations.…”

Oxide Layer Enhances Photocurrent Gain of the Planar MAPbI3 Photodetector

“…Similar device performance losses with the increase of the TiO 2 layer thickness were also reported for the perovskite solar cells. [16] By discussing the gain mechanism in CH 3 NH 3 PbI 3 photodetector, Dong et al [17] also assumed that the hole trapping is much more efficient. Figure 3 shows photoconductivity gain and responsivity (photocurrent density divided by illumination power density) values of the investigated devices, which we have calculated from the J-V curves.…”

Improving the Performance of Perovskite Solar Cells Through Solvent Vapor Annealing‐based Morphology Control of the Hole‐Transport Layer

“…[1][2][3][4] As a result, perovskite solar cells (PSCs) have been actively investigated and power conversion efficiencies (PCEs) have been rapidlyi mprovedt o2 2.1 %, [5] whichi ndicates great potential for futurecommercialization. [1][2][3][4][5][6] Methylammonium lead halide (CH 3 NH 3 PbX 3 ,X = Cl, Br, or I) perovskites are the most widely used optical absorbers in PSCs;t he absorber layer is typically sandwiched between the hole-and electron-transport materials. [5][6][7] As PSCs originate from dye-sensitized solar cells (DSSCs), am esoporous and compactT iO 2 layer is usuallye mployed as the electrontransport material.…”

“…[1][2][3][4][5][6] Methylammonium lead halide (CH 3 NH 3 PbX 3 ,X = Cl, Br, or I) perovskites are the most widely used optical absorbers in PSCs;t he absorber layer is typically sandwiched between the hole-and electron-transport materials. [5][6][7] As PSCs originate from dye-sensitized solar cells (DSSCs), am esoporous and compactT iO 2 layer is usuallye mployed as the electrontransport material. [1][2][3][4][5][6][7] On the other hand, 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) is most commonly used as the hole-transport material for fabricatingP SCs.…”

“…[5][6][7] As PSCs originate from dye-sensitized solar cells (DSSCs), am esoporous and compactT iO 2 layer is usuallye mployed as the electrontransport material. [1][2][3][4][5][6][7] On the other hand, 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) is most commonly used as the hole-transport material for fabricatingP SCs. [1,4,7] To further enhance the performance of PSCs,p otential improvementsi nt he form of developingn ew perovskites,d iscovering new charge transport materials,and designing new architectures have been actively investigated.…”