High‐Efficiency Polymer Solar Cells Over 13.9% With a High V_OC Beyond 1.0 V by Synergistic Effect of Fluorine and Sulfur

Abstract

A novel phenyl substituted benzo(1,2‐b:4,5‐b’)dithiophene (BDT) derivative containing both fluorine and sulfur atoms is designed and synthesized. Furthermore, a wide bandgap polymer PBTA‐PSF based on the derivative shows a low highest occupied molecular orbital energy level and slightly reduces the donor materials’ optical bandgap, which has a complementary absorption with a narrow‐bandgap n‐type small molecule ITIC. As a result, a power conversion efficiency of 13.91% is achieved with a high open‐circuit voltage of 1.01 V, and a large short‐circuit current density of 18.51 mA cm−2. The result demonstrates that PBTA‐PSF is a promising candidate for high‐performance donor and phenyl‐containing BDT derivatives and has potential in the design of high‐performance polymers for organic photovoltaics.

Solution-processible Cd-doped ZnO nanoparticles as an electron transport layer to achieve high performance polymer solar cells through improve conductivity and light transmittance

“…The following discussion further confirmes that CZO acts as ETL, accounting for the theory of FF enhancement in doped system. The J-V curves of electron-only (μe ) devices along with individual Cd-doped ratios are shown in Fig (d), we elucidate the carrier mobilities of ETL by adopting the space-charge limited current (SCLC) model [33][34][35][36][37]. Electron-only devices were manufactured (ITO/CZO/PTB7-Th:…”

Significantly Enhanced Molecular Stacking in Ternary Bulk Heterojunctions Enabled by an Appropriate Side Group on Donor Polymer

“…[ 44–47 ] We have reported a promising polymer donor with phenyl side group modified BDT (named PBTA‐PS), which delivered high PCE of 11.83% with ITIC as acceptor. [ 48 ] After introducing 20% IT‐4F (weight ratio) into the PBTA‐PS:ITIC system, the ternary PSC shows simultaneously increased J SC and FF, resulting in a high PCE of 13.27%. The improvement of device performance could be attributed to the broadened photoresponse, optimized molecular packing and the good compatibility of three components.…”

Ternary Polymer Solar Cells with High Efficiency of 14.24% by Integrating Two Well‐Complementary Nonfullerene Acceptors

“…Besides, the ternary solar cells exhibit higher overall charge collection efficiency (calculated by J ph / J sat ) of 95% than PBTA‐PS:LA1 (88%) and PBTA‐PS:6TIC (83%) binary devices under short‐circuit condition, indicating better exciton generating and charge collection, which could partly explain the enhanced photo response at the wavelength of 750–900 nm . To further investigate the charge recombination process, J SC versus light intensity ( P light ) was plotted, which follows the power–law dependence of J SC ∝ P α . The α approaching 1 indicates negligible bimolecular recombination.…”