Abstract
Recently, much progress has been achieved in the lab prototype perovskite solar cells (PSCs), however, the challenging toward the commercial production of PSCs still remains, which is their low stability due to the inherent moisture sensitivity of the perovskite photoactive layer. In this work, a hydrophobic hole modification layer, zinc phthalocyanine (ZnPc), is introduced to the typical planer hetero-junction (PHJ) structure to improve the device performance and prevent moisture. The ZnPc based devices show an improved power conversion efficiency (PCE) of 16.8% compared to 15.1% for the unmodified devices, and highly enhanced long-term stability (91% of initial PCE remains after 2400h), which is the best report for PSCs in ambient environment without sealing. In addition, pulsed laser deposition (PLD) technique is used to prepare electron collection layer Nb-doped TiOx in PSC fabrication process. Devices with large area (225mm2) and flexibility were also fabricated in this study to demonstrate the potential practical application of this strategy. This work paves a way for the developments of PSCs with long-term stability and demonstrates a strategy toward practical applications for PSCs.
In this work, Nd-doped TiOx by pulsed laser deposition and hydrophobic ZnPc by rotary vacuum thermal evaporation were firstly employed as electron and hole transport layers to improve the PSC performance. Such improvement lends crucial support to the enhanced injection and extraction of photo-generated carriers at the electron transport layer/perovskite interface and hole transport layer/perovskite interface, which sequentially trigger remarkable increases in Jsc and Voc. More importantly, the hole modification layer ZnPc could also prevent moisture permeation into the perovskite photoactive layer, improving the long-term stability of PSCs. After optimization, the device exhibits an optimum PCE of 16.8% and the long-term stability (91% of initial PCE remains after 2400h), which is the best report for PSCs in ambient environment without any sealing until now. Furthermore, large area device (225mm2) and flexible devices were also fabricated for demonstrating the potential practical application prospects. This work offers novel insights on the PSC devices with respect to high permanence and long-term stability. [Display omitted]
•The modified PSCs exhibited a long-term stability over 2400h aging.•PLD was firstly introduced to compact Nb-doped TiOx films preparation in the PSCs.•The PSCs showed an improved PCE of 16.8% due to the reduced carrier recombination.•PSCs with large area (225mm2) and flexibility were also fabricated.•Best water contact angle (115.4°) proved the hydrophobic property of ZnPc films.