Fabrication and Characterization of CH3NH3PbI3−x−yBrxCly Perovskite Solar Cells

Abstract

Fabrication and characterization of CH 3 NH 3 PbI 3´x´y Br x Cl y perovskite solar cells using mesoporous TiO 2 as electron transporting layer and 2,2 1 ,7,7 1 -tetrakis-(N,N-di-4-methoxypheny lamino)-9,9 1 -spirobifluorene as a hole-transporting layer (HTL) were performed. The purpose of the present study is to investigate role of halogen doping using iodine (I), bromine (Br) and chlorine (Cl) compounds as dopant on the photovoltaic performance and microstructures of CH 3 NH 3 PbI 3´x´y Br x Cl y perovskite solar cells. The X-ray diffraction identified a slight decrease of crystal spacing in the perovskite crystal structure doped with a small amount of I, Br, and Cl in the perovskite compounds. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) showed the perovskite crystal behavior depended on molar ratio of halogen of Pb, I, Br and Cl. Incorporation of the halogen doping into the perovskite crystal structure improved photo generation, carrier diffusion without carrier recombination in the perovskite layer and optimization of electronic structure related with the photovoltaic parameters of open-circuit voltage, short-circuit current density and conversion efficiency. The energy diagram and photovoltaic mechanisms of the perovskite solar cells were discussed in the context of the experimental results.

Revealing the Cooperative Chemistry of the Organic Cation in the Methylammonium Lead Triiodide Perovskite Semiconductor System

“…The reduction in E g is indeed very large. However, encouragingly, it is comparable with the experimental bandgap of 1.53 eV reported for the tetragonal phase of the MAPbI 3 thin‐film semiconductor; the value of this gap for the other phases of the system were reported lying between 1.50 and 1.70 eV. This result shows that the length (and dimensions) are both important in the gas phase calculation for recovering the actual nature of the bandgap of the MAPbI 3 thin‐film.…”

Fabrication of Perovskite-Type Photovoltaic Devices with Polysilane Hole Transport Layers

“…In Figure 9 Finally, composition ratio of Pb and I atoms presented in Table 2 is very sensitive to photovoltaic performance. Compared with photovoltaic devices fabricated without air blow-assisted spin-coating method [25] [29] [30], the present CH 3 NH 3 PbI 3 layers were Pb-rich and I-poor, suggesting that the CH 3 NH 3 PbI 3 layers were n-type. Types of conductivity of perovskite compounds strongly depend on composition ratio of themselves.…”

“…Poly(ethylene glycol) (Nacalai Tesque, averaged molecular number: 20,000, 10 mg), acetylacetone (Wako Pure Chemical Industries, 10 μL) and a surfactant (Sigma-Aldrich, Triton X-100, 5 μL) were added in the TiO 2 paste. The paste was stirred for 30 [33]. The molar ratio of the solutes was 1:1.…”

Characterization and Photovoltaic Properties of BiFeO3 Thin Films

“…In the present study, the theoretical V oc of the BiFeO 3 /CH 3 NH 3 PbI 3 photovoltaic cell was 0.9-1.1 V. These values are greater than the present V oc , as shown in Figure 4a. The obtained low V oc was considered to be due to large V loss associated with trap states in the CH 3 NH 3 PbI 3 layer, presumably generated due to partial separation of PbI 2 from the CH 3 NH 3 PbI 3 [23,24,[26][27][28]. In addition, it is considered that grains of the present CH 3 NH 3 PbI 3 were small.…”