Solid Solvation Assisted Electrical Doping Conserves High‐Performance in 500 nm Active Layer Organic Solar Cells

Abstract

Organic solar cells (OSCs) process fascinating solution‐printing capability to achieve low‐cost and large‐scale manufacture. However, the rapid power conversion efficiency (PCE) decay with active layer thickness enlargement inhibits the implement of OSCs’ potential advantages. To overcome the bottlenecks of PCE decay in thick active layer OSCs, the electrical doping with componential selectivity in bulk heterojunction (BHJ) film is achieved by introducing a solid solvation additive. Benefiting from the higher exciton splitting efficiency together with the longer drift (Ldr) and diffusion (Ldiff) lengths, an OSC with 100 nm BHJ film demonstrates a PCE increment from 16.44% to 18.24% with prolonged dark and illuminated storage stabilities. Applying the solid solvation assisted (SSA) doping method in the OSCs with 500 nm active layer, the PCE significantly increases by 31.9%, from the original value of 11.79% to 15.55%. It further improves to 15.84% in a ternary blend thick‐film device, which is the record value to the best of our knowledge. Besides, the SSA doping narrows the PCE gap between the 0.04 and 1 cm2 devices. All improvements demonstrate the great potential of SSA doping for OSC commercial manufacture, since it optimizes the photovoltaic performance under all practical conditions of long‐term, thick‐film, and large‐area.

Eliminating the Imbalanced Mobility Bottlenecks via Reshaping Internal Potential Distribution in Organic Photovoltaics

“…In addition to the 100 nm-thick lab devices, we expect that this strategy could be more effective in thick film devices. [47] Since the counter electrode doping strategy focuses on the electric factors, it is compatible with other OSC optimizing strategies such as material synthesis and microstructure modification. We believe this will inspire further OSC performance breakthroughs as an essential tool.…”

Identifying and Amplifying the Spontaneously Formed Photo‐Charge Contribution in Opaque and Semitransparent Organic Photovoltaics

“…To identify the key morphology factor that determines the SP portion, we conducted Pearson correlation analysis to correlate these conflicting parameters with E a and L EX+SP (Figure 3e). [63,64] The R f/e has relatively weak correlation with both of lamellar and 𝜋-𝜋 stacking order. More than that, the R f/e demonstrates opposite correlations with the CL and peak area in 𝜋-𝜋 stacking direction.…”

“…On the contrary, any addition of N-DMBI decreases the J SC in D18:N4 device, which emphasizes that the n-doping functions in case of SP existence (Figure S26 and Table S6, Supporting Information). Since the optimization of the halogenated volatile solid additives [13,[69][70][71][72][73][74][75] and N-DMBI [19,63,76,77] on OSCs does not rely on specific NFAs' chemical structures of side chains and end groups, we propose that our two steps optimizing strategy is widely applicable in SP contained NFAs. We further examine this assumption in ( luoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitri le (N3), which only differs in the branching position of alkyl chains with N4 (Figure 1a; Figure S27a, Supporting Information).…”

High‐Performance Binary All‐Polymer Solar Cells with Efficiency Over 18.3% Enabled by Tuning Phase Transition Kinetics

“…[10][11][12][13] Unfortunately, the performance of All-PSCs has lagged behind that of OSCs based on non-fullerene small molecular acceptors, primarily due to non-optimal BHJ morphology. [14][15][16][17][18] Therefore, more efforts should be made to deeply understand and regulate the morphology formation to advance the development of All-PSCs.…”