Reducing Interfacial Losses in Solution-Processed Integrated Perovskite-Organic Solar Cells

Abstract

Low bandgap organic semiconductors have been widely employed to broaden the light response range to utilize much more photons in the inverted perovskite solar cells (PSCs). However, the serious charge recombination at the heterointerface contact between perovskite and organic semiconductors usually leads to large energy loss and limits the device performance. In this work, a titanium chelate, bis(2,4-pentanedionato) titanium(IV) oxide (C 10 H 14 O 5 Ti), was directly used as an interlayer between the perovskite layer and organic bulk heterojunction layer for the first time. Impressively, it was found that C 10 H 14 O 5 Ti can not only increase the surface potential of perovskite films but also show a positive passivation effect toward the perovskite film surface. Drawing from the above function, a smoother perovskite active layer with a higher work function was realized upon the use of C 10 H 14 O 5 Ti. As a result, the C 10 H 14 O 5 Ti-modified integrated devices show lower interfacial loss and obtain the best power conversion efficiency (PCE) of up to 20.91% with a high voltage of 1.15 V. The research offers a promising strategy to minimize the interfacial loss for the preparation of high-performance perovskite solar cells.

Enhancing the Efficiency and Stability of Inverted Formamidinium-Cesium Lead-Triiodide Perovskite Solar Cells through Lewis Base Pretreatment of Buried Interfaces

“…The interaction between the BA molecule and perovskite was detected by Fourier transform infrared (FTIR) spectroscopy . As shown in Figure d, characteristic stretching vibrations of CO arose in pure BA film at about 1656.07 cm –1 . Perovskite and PbI 2 specimen also appeared CO bond stretching at 1649.80 cm –1 after BA was modified. , The characteristic stretching vibrations of the CO group from BA indicate the interaction between BA molecules and perovskite through bonding with PbI 2 .…”