High Performance Nanostructured Silicon–Organic Quasi <i>p</i>–<i>n</i> Junction Solar Cells <i>via</i> Low-Temperature Deposited Hole and Electron Selective Layer

Abstract

PSS hinders the power conversion efficiency (PCE) in comparison with those of traditional p-n junction. Here, a strong inversion layer was formed on n-Si surface by inserting a layer of 1, 4, 5, 8, 9, 11-hexaazatriphenylene hexacarbonitrile (HAT-CN), resulting in a quasi p-n junction. External quantum efficiency spectra, capacitance-voltage, transient photovoltage decay and minority charge carriers life mapping measurements indicated that a quasi p-n junction was built due to the strong inversion effect, resulting in a high Φb and Vbi. The quasi p-n junction located on the front surface region of silicon substrates improved the short wavelength light conversion into photocurrent. In addition, a derivative perylene diimide (PDIN) layer between rear side of silicon and aluminum cathodes was used to block the holes from flowing to cathodes. As a result, the device with PDIN layer also improved photoresponse at longer wavelength. A champion PCE of 14.14% was achieved for the nanostructured silicon-organic device by combining HAT-CN and PDIN layers. The low temperature and simple device structure with quasi p-n junction promises cost-effective high performance photovoltaic techniques.