Stable Organic–Inorganic Perovskite Solar Cells without Hole‐Conductor Layer Achieved via Cell Structure Design and Contact Engineering. (20th May 2016)

• Record Type: Journal Article
• Authors: Yu, Zhenhua; Chen, Bolei; Liu, Pei; Wang, Changlei; Bu, Chenhao; Cheng, Nian; Bai, Sihang; Yan, Yanfa; Zhao, Xingzhong
• Is Part Of: Advanced functional materials. Volume 26:Number 27(2016)
• Page Start: 4866
• Page End: 4873
• Publication Date: 2016-05-20
• Subjects: all‐solution fabrication process in the air -- carbon/MAI hybrid contacts engineering -- hole‐transport material free -- low cost -- stable perovskite solar cells; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201504564
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract : Within the past few years, the record efficiency of inorganic–organic perovskite solar cell (PSC) has improved rapidly up to over 20%. However, the viability of commercialization of the PSC technology has been seriously questioned due to the moisture‐ and thermal‐induced instabilities. Here, it is demonstrated that these issues may be mitigated via cell structure design and contact engineering. By employing the hole‐conductor layer‐free cell structure and a bi‐layer back contact consisting of a carbon/CH3 NH3 I composite layer and a compact hydrophobic carbon layer, the PSCs have shown excellent stability, inhibiting moisture ingression and heat‐induced perovskite degradation. It is found that, the unique bi‐layer contact enables the optimization of perovskite absorbers during thermal stress. As a result, instead of degradation, the devices present enhanced performance under heating at 100 °C for 30 min. The best‐performing cell shows a final efficiency of 13.6% from an initial efficiency of 11.3% after thermal stress. Upon encapsulation, these cells can even retain 90% of the initial efficiencies after water exposure and over 100% initial efficiency under thermal stress at 150 °C for half an hour. This approach provides a facile way for stabilizing the PSCs and opens a door for viable commercialization of the emerging PSC technology. Abstract : To mitigate the instability of perovskite solar cells via device structure design and contact engineering, a hole‐conductor layer‐free structure of device and a unique bi‐layer hybrid carbon back contact are adopted. The cells not only achieve an enhanced efficiency of 13.6% from the initial 11.3% after 100 °C treatment, but also exhibit excellent moist and thermal stability.