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Hybrid organic-inorganic perovskite solar cells (PSCs) are the novel fourth-generation solar cells, with impressive progress in the last few years. MAPbI 3 is a cost-effective material used as an absorber layer in PSCs. Due to the different diffusion length of carriers, the electron transporting material (ETM) plays a vital role in PSCs' performance. ZnO ETM is a promising candidate for low-cost and high-efficiency photovoltaic technology. In this work, the normal n-i-p planar heterojunction structure has been simulated using SCAPS-1D. The influence of various parameters such as the defect density, the thickness of the MAPbI 3 layer, the temperature on fill factor, the open-circuit voltage, the short circuit current density, and the power conversion efficiency are investigated and discussed in detail. We found that a 21.42% efficiency can be obtained under a thickness of around 0.5 μm, and a total defect of 10 13 cm −3 at ambient temperature. These simulation results will help fabricate low-cost, high-efficiency, and low-temperature PSCs.

Strong white and blue photoluminescence (PL) from as-grown silicon nanocrystals (nc-Si) in SiNx films prepared by remote plasma enhanced chemical vapour deposition using SiCl4/NH3 mixtures is reported. The colour and intensity of the PL could be controlled by adjusting the NH3 flow rate. Samples with white emission were annealed at 1000 °C, obtaining a strong improvement of the PL intensity with a blue colour. The PL can be attributed to quantum confinement effect in nc-Si embedded in SiNx matrix, which is improved when a better passivation of nc-Si surface with chlorine and nitrogen atoms is obtained. The size, density and structure of the nc-Si in the as-grown and annealed films were confirmed and measured by high-resolution transmission electron microscopy.

Silicon nanocrystals embedded in silicon nitride films were grown by direct plasma enhanced chemical vapor deposition at 300 degrees C, using mixtures of SiH2Cl2/NH3/H2/Ar. The films composition and chemical stability was tested by Fourier Transform Infrared Spectroscopy and Rutherford Backscattering Spectroscopy. The influence of hydrogen abundance during the deposition process on the photoluminescence of as-grown samples was studied as a function of the radiofrequency power and hydrogen dilution flow rate. In situ Optical Emission Spectroscopy allowed the diagnostic of the species in the plasma region and their general trends as a function of the radiofrequency power. The changes in the hydrogen content and silicon incorporation to the film as a function of the radiofrequency power were discussed in terms of silicon nanocrystals formation and growth in the silicon nitride matrix. The photoluminescence emission from the as-grown samples was found to red-shift with increasing hydrogen abundance. This observation is consistent with the increase in silicon content associated to nc-Si of larger size. On the other hand, the photoluminescence intensity was observed to decrease for very high radiofrequency powers and hydrogen dilutions. High Resolution Transmission Electron Microscopy confirmed the presence of silicon nanocrystals embedded in the amorphous silicon nitride matrix and allowed the correlation between the nanocrystals size and the photoluminescence emission energy using the quantum confinement model.

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