A photochemical layer-by-layer solution process for preparing organic semiconducting thin films having the right material at the right place

Abstract

A mild and versatile solution process enables the controlled preparation of multicomponent organic small-molecule thin films.

Layer‐by‐Layer Solution Processing Method for Organic Solar Cells

“…The three‐layer device can maintain the effective dissociation of excitons, while improving the efficiency of charge transport and extraction, so that a PCE of 4.7% is obtained. [ 16 ]…”

“…[10][11][12] Compared with BHJ, the LbL solution processing method with many advantages is a cost-effective alternative way. [13][14][15][16] Firstly, good contact between the material and the corresponding electrodes can be ensured by sequentially spin coating materials. Second, LbL solution-processed OSCs could optimize the donor layer and acceptor layer separately to make the two components ideally distribute in the vertical direction.…”

A Windmill-Shaped Molecule with Anthryl Blades to Form Smooth Hole-Transport Layers via a Photoprecursor Approach

“…The maximum benefit of this structure can be gained by optimizing each sublayer in terms of material, morphology, and thickness. As a proof of this concept, we have demonstrated that a ternary p-i-n OPV can achieve a power-conversion efficiency (PCE) almost twice as high as the corresponding simple bulk-heterojunction (BHJ) device (5.9 vs. 3.0%) [20].…”

“…One of the remaining challenges with the photoprecursor approach is establishing moleculardesign principles for highly effective, robust p-sublayer (or hole-transport) materials. The compounds employed in our previous studies (2,6-di(thiophen-2-yl)anthracene (DTA) and 2,8diphenylanthra[1,2-b:5,6-b']dithiophene (PhBADT), Figure 2) are not ideal in that they are strongly aggregating and form highly rough surfaces [19][20][21]. Indeed, the roughness was too high to determine the effective film thickness, and thus it was not possible to estimate hole mobilities in those materials by the space-charge-limited-current (SCLC) method.…”

Improvement in interlayer structure of p–i–n-type organic solar cells with the use of fullerene-linked tetrabenzoporphyrin as additive

“…[43][44][45][46][47][48][49][50][51][52] Since the conversion of the precursor into the semiconducting material involves a decrease in the solubility owing to the induced structural changes, a three-layered p-i-n structure with the abovementioned vertical-phase separation can be achieved through solution-based processes. [53][54][55][56][57] Here, "i" stands for the interlayer between the p-and n-layers. Similar to the BHJ lm, this layer consists of blended p-and n-type materials.…”