Low-temperature easy-processed carbon nanotube contact for high-performance metal- and hole-transporting layer-free perovskite solar cells

摘要

Expensive and energy-consuming vacuum process of metal deposition with ambient-unstable hole transporters are incompatible with large-scale and low-cost production of perovskite solar cells (PSCs) and thus hampers their commercialization. For the first time, we demonstrate cost-effective novel carbon nanotube (CNT) paste that was applied to FTO substrate by the facile doctor blade method and processed at low temperature (100 degrees C). Herein we report a new method of cost-efficient perovskite solar cells with the use of conventional hole transporters by directly clamping a selective hole extraction electrode made of CNT and a TiO2/perovskite photoanode. Most importantly, under optimized conditions in the absence of an organic hole-transporting material and metal contact, CH3NH3PbI3 and CNTs formed a solar cell with an efficiency of up to 7.83%. The PSC devices are fabricated in air without high-vacuum deposition which simplifies the processing and lowers the threshold of both scientific research and industrial production of PSCs. Electrochemical impedance spectroscopy demonstrates good charge transport characteristics of CEs on the photovoltaic performance of devices. The PSCs exhibited good stability over 50 h. The abundance, low cost, and excellent properties of the CNT material offer wide prospects for further applications in PSCs. (C) 2016 Elsevier B.V. All rights reserved.