Transport layer optimization for high-efficiency and stable planar n-i-p perovskite solar cells

涂保

11653009

博士

APPLIED PHYSICS AND MATERIALS ENGINEERING

何祝兵,李海峰,汤子康

2020-07-03

2020-07-07

澳门大学

澳门

Pollution-free renewable energy is becoming important at an accelerated pace to promote the comfortable survival of human civilization. Solar energy is inexhaustible and abundantly surface energy which can satisfy the growing energy demand. With outstanding optical and electrical properties of perovskite, perovskite solar cells (PSCs) has attracted tremendous attention and shown its simple manufacturing process and rapidly increased power convention efficiency (PCE). But there are also many obstacles in their development process, mainly include the further to be improved PCE, poor stability, small cell area and toxicity. And here we mainly committed to solving the problems around PCE and stability. Transport layer plays a critical role in the final performance, and optimization of transport layer is conformed as an effect strategy to bring about high-performance and stable PSCs. Based on these, transport layer optimization was proposed to achieve stable PSCs with high efficiency. Firstly, electron transport layer (ETL) optimization was realized by molecular doping of SnO2. After n-type doping, the electrons are transferred from high polarly σ-bond mainly to the peripheral tin atoms instead of directly connected tin atoms, results in the presence of delocalized electrons at the surface, and consequently increased conductivity and decreased work function. These in turn results in an increased built-in field and a decreased energy barrier at SnO2/perovskite interface, enables the PCE improved to 20.69%. Following, ETL optimization was realized by defect passivation of SnO2. Based on the novel method proposed, SnO2 was transferred into H2N-SiOX@SnO2, which could passivate the defects and alleviate charge accumulation effectively, results in an obvious improvement in open-circuit voltage (Voc) and PCE, along with improved stability. Meanwhile, hole transport layer (HTL) optimization was also realized by introducing dopant free hole transport materials (HTMs) to replace 2,2',7,7'tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD). Our results suggested that BTTI-C6 based device show an encouraging PCE (19.69%) which is comparable to the reference, and largely improved long-term illumination and thermal stability compared to Spiro-OMeTAD based devices. Overall, improved efficiency and stability are achieved by transport layer optimization, and some new novel optimization methods are proposed, which can provide guidance for further understanding around PSCs and improve performance.

planar n-i-p perovskite solar cells transport layer optimization molecular doping defect passivation dopant free HTMs

英语

联合培养

南方科技大学

Tu B. Transport layer optimization for high-efficiency and stable planar n-i-p perovskite solar cells[D]. 澳门. 澳门大学,2020.