Adjusted Bulk and Interfacial Properties in Highly Stable Semitransparent Perovskite Solar Cells Fabricated by Thermocompression Bonding between Perovskite Layers

Abstract

In order to shield perovskite solar cells (PSCs) fromextrinsicdegradation factors and ensure long-term stability, effective encapsulationtechnology is indispensable. Here, a facile process is developed tocreate a glass-glass encapsulated semitransparent PSC usingthermocompression bonding. From quantifying the interfacial adhesionenergy and considering the power conversion efficiency of devices,it is confirmed that bonding between perovskite layers formed on ahole transport layer (HTL)/indium-doped tin oxide (ITO) glass andan electron transport layer (ETL)/ITO glass can offer an excellentlamination method. The PSCs fabricated through this process have onlyburied interfaces between the perovskite layer and both charge transportlayers as the perovskite surface is transformed into bulk. The thermocompressionprocess leads the perovskite to have larger grains and smoother, denserinterfaces, thereby not only reducing defect and trap density butalso suppressing ion migration and phase segregation under illumination.In addition, the laminated perovskite demonstrates enhanced stabilityagainst water. The self-encapsulated semitransparent PSCs with a wide-band-gapperovskite (E (g) & SIM; 1.67 eV) demonstratea power conversion efficiency of 17.24% and maintain long-term stabilitywith PCE > & SIM;90% in the 85 & DEG;C shelf test for over 3000h and with PCE > & SIM;95% under AM 1.5 G, 1-sun illuminationinan ambient atmosphere for over 600 h.