Controllable Spatial Configuration on Cathode Interface for Enhanced Photovoltaic Performance and Device Stability

Abstract

The molecular structure of cathode interface modification materials can affect the surface morphology of the active layer and key electron transfer processes occurring at the interface of polymer solar cells in inverted structures mostly due to the change of molecular configuration. To investigate the effects of spatial configuration of the cathode interfacial modification layer on polymer solar cells device performances, we introduced two novel organic ionic salts (linear NS2 and three-dimensional (3D) NS4) combined with the ZnO film to fabricate highly efficient inverted solar cells. Both organic ionic salts successfully decreased the surface traps of the ZnO film and made its work function more compatible. Especially NS4 in three-dimensional configuration increased the electron mobility and extraction efficiency of the interfacial film, leading to a significant improvement of device performance. Power conversion efficiency (PCE) of 10.09% based on NS4 was achieved. Moreover, 3D interfacial modification could retain about 92% of its initial PCE over 160 days. It is proposed that 3D interfacial modification retards the element penetration-induced degradation without impeding the electron transfer from the active layer to the ZnO film, which significantly improves device stability. This indicates that inserting three-dimensional organic ionic salt is an efficient strategy to enhance device performance.

Graphdiyne as a Host Active Material for Perovskite Solar Cell Application

“…As shown in Figure i, the average carrier lifetime of pure MAPbI 3 and MAPbI 3 (GD) are 73.3 and 16.8 ns. The result indicates a faster transfer of charge for MAPbI 3 (GD) film, which leads to increased J sc and PCE values. , …”

“…To understand the origin of the J sc increment, the J – V curves of hole-only devices with the structure of ITO/Al/MAPbI 3 or MAPbI 3 (GD)/Al and ITO/MoO 3 /MAPbI 3 or MAPbI 3 (GD)/MoO 3 /Al were measured to test their hole-extraction behaviors. , In Figure e,f, the J – V curves show that GD, as the host active layer, exhibits higher current density at the same forward bias than the undoped one, indicating a better capability of electron and hole extraction of MAPbI 3 (GD). The G max and P values are plotted in Figure g,h to investigate the influence of MAPbI 3 (GD) on the PSCs. , From Figure g, with the increase of effective voltage, the saturation photocurrent ( J sat ) in the device with MAPbI 3 (GD) reaches earlier than that with MAPbI 3 . Generally, the saturated photocurrent correlates to the maximum exciton generation rate ( G max ).…”

Studies of Graphdiyne‐ZnO Nanocomposite Material and Application in Polymer Solar Cells

“…Analogous to GD, the fascinating properties of relatively high electron mobility, suitable energy levels, remarkable optical transmittance as well as easy preparation at a low temperature draw our attention to ZnO, which is regarded as an attractive material for the application of electron transport layers (ETLs) . Whereas a major concern of ZnO interlayer lies in its surface defects, which results in terrible electron mobility and high recombination of charge, consequently leading to a poor performance of the ZnO based devices .…”

TTA as a potential hole transport layer for application in conventional polymer solar cells

“…As shown in Fig. 4 (a), the optical transmittance spectrum of ITO/TTA at the wavelength range of 30 0-80 0 nm shows over 80% average transmittance, indicating sufficient reaching of light to active layer for http://engine.scichina.com/doi/10.1016/j.jechem.2019.07.005 energy conversion [33] . To clarify the chemical structure of TTA on ITO substrates, X-ray photoelectron spectroscopy (XPS) was performed as displayed in Fig.…”