2021 Energy Environ. Sci. (IF 38.532) : 17% Highest PCE! Small-molecule-based OSC

　　Energy & Environmental Science (IF 38.532) published a study in September 2021. Scientists built small-molecule-based organic solar cells (SM-OSC) with a ternary heterojunction (BHJ) layer to achieve the highest efficiency of the current SM-OSC.

　　Compared with polymer-based organic solar cells (OSCs), it is still very challenging for small-molecule organic solar cells (SM-OSC) to obtain a nano-scale bicontinuous network structure in the active layer. In this research, scientists constructed SM-OSC based on the B1:BO-2Cl:BO-4Cl ternary heterojunction (bulk heterojunction, BHJ) layer.

　　Through Enlitech’s SS-X solar simulator and the QE-R quantum efficiency measurement system for spectral response measurement, the results obtained from transient absorption, time-resolved photoluminescence spectroscopy and device physical analysis showed that the ternary battery with the best composition (weight ratio B1:BO-2Cl:BO-4Cl = 1: 0.5: 0.5) exhibited better performance. Fast charge transfer process and higher and more symmetrical carrier mobility were achieved and obtained 17.0% (certified as 16.9%) power conversion efficiency (PCE), which is the highest efficiency of SM-OSC. In addition to the EQE (External Quantum Efficiency) spectrum analysis of solar cells, the Quantum Efficiency Measurement System of Enlitech also provides Jsc (short-circuit current density) comparison for the short-circuit current of solar cells under the solar simulator to prove the authenticity of the experiment. At the same time, the solar simulator and KA-6000 software of Enlitech also provide monitoring of the short-circuit current over time to prove the stability of the solar cell!