Overcoming the Open-Circuit Voltage Losses in Narrow Bandgap Perovskites for All-Perovskite Tandem Solar Cells.

Narrow-bandgap (NBG) perovskite solar cells based on tin-lead mixed perovskite absorbers suffer from significant open-circuit voltage ( ) losses due primarily to a high defect density and charge carrier recombination at the device interfaces. In this study, the losses in NBG perovskite single junction cells ( = 1.21 eV) are addressed.

MXene-Embedded PEDOT:PSS Hole-Transport Material for Lead-Free Perovskite Solar Cells.

Improving the energy alignment between charge-transport layers and the perovskite is crucial for further enhancing the photovoltaic performance of tin-based perovskite solar cells (PSCs). Herein, the role of TiCT MXene in a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layer (HTL) on the photovoltaic properties of PSCs is investigated as a function of its concentration. An improved perovskite film formation with reduced pinhole density and a more uniform contact potential difference is noted when MXene is embedded in the PEDOT:PSS HTL.