The behavior of H inβ-Ga₂O₃ is of substantial interest because it is a common residual impurity that is present inβ-Ga₂O₃, regardless of the synthesis methods. Herein, we report the influences of H-plasma exposure on the electric and optical properties of the heteroepitaxialβ-Ga₂O₃ thin films grown on sapphire substrates by chemical vapor deposition. The results indicate that the H incorporation leads to a significantly increased electrical conductivity, a greatly reduced defect-related photoluminescence emission, and a slightly enhanced transmittance, while it has little effect on the crystalline quality of theβ-Ga₂O₃ films. The significant changes in the electrical and optical properties ofβ-Ga₂O₃ may originate from the formation of shallow donor states and the passivation of the defects by the incorporated H. Temperature dependent electrical properties of the H-incorporatedβ-Ga₂O₃ films are also investigated, and the dominant scattering mechanisms at various temperatures are discussed.The behavior of H inβ-Ga₂O₃ is of substantial interest because it is a common residual impurity that is present inβ-Ga₂O₃, regardless of the synthesis methods. Herein, we report the influences of H-plasma exposure on the electric and optical properties of the heteroepitaxialβ-Ga₂O₃ thin films grown on sapphire substrates by chemical vapor deposition. The results indicate that the H incorporation leads to a significantly increased electrical conductivity, a greatly reduced defect-related photoluminescence emission, and a slightly enhanced transmittance, while it has little effect on the crystalline quality of theβ-Ga₂O₃ films. The significant changes in the electrical and optical properties ofβ-Ga₂O₃ may originate from the formation of shallow donor states and the passivation of the defects by the incorporated H. Temperature dependent electrical properties of the H-incorporatedβ-Ga₂O₃ films are also investigated, and the dominant scattering mechanisms at various temperatures are discussed.

The record power conversion efficiency of small-area perovskite solar cells has impressively exceeded 25%. For commercial application, a large-area device is the necessary next step. Recently, significant progress has been achieved in fabricating efficient large-area perovskite solar cells. In this review, we will summarize recent achievements in large-area perovskite solar cells including the deposition methods as well as growth control of the large-area, high-quality perovskite layer and also the charge transport layer. Finally, we will give our insight into large-area perovskite solar cells.

Although perovskite solar cells containing methylamine cation can show high power conversion efficiency, stability is a concern. Here, methylamine-free perovskite material Cs_xFA_1–xPbI₃ was synthesized by a one-step method. In addition, we incorporated smaller cadmium ions into mixed perovskite lattice to partially replace Pb ions to address the excessive internal strain in perovskite structure. We have found that the introduction of Cd can improve the crystallinity and the charge carrier lifetime of perovskite films. Consequently, a power conversion efficiency as high as 20.59% was achieved. More importantly, the devices retained 94% of their initial efficiency under 1200 h of continuous illumination.