posted on 2023-11-30, 18:34authored bySeokjoo Ryu, Bumjin Gil, Beomsoo Kim, Jinhyun Kim, Byungwoo Park
Perovskite
solar cells (PSCs) are gaining significant interest
as the future of photovoltaics owing to their superior performance
and cost-effectiveness. Nevertheless, traps in PSCs have emerged as
issues that adversely affect the efficiency and stability of the devices.
In this study, the methylammonium chloride (MACl) additive and phenyltrimethylammonium
iodide (PTMAI) posttreatment were applied to passivate bulk and surface
defects. Furthermore, variations of the traps’ quantitative
spatial arrangement have been monitored by using the drive-level capacitance
profiling (DLCP) analysis. A similar magnitude of trap reduction was
observed for the bulk perovskite layer and two interfaces (electron
transport layer (ETL)/perovskite and hole transport layer (HTL)/perovskite)
with an optimal concentration of the MACl additive. However, the effect
of perovskite posttreatment in reducing the trap density was much
more noticeable at the HTL/perovskite interface compared to the bulk
and ETL/perovskite regions. This observation was reinforced by the
outcomes of the 500 h thermal stability tests at 60 °C from seven
independent batches, which demonstrated a substantial suppression
of trap accumulation, particularly at the HTL/perovskite interface,
by an order of magnitude.