Interfacial Modification in Organic and Perovskite Solar Cells

Abstract

Organic bulk heterojunction solar cells (OSCs) and hybrid halide perovskite solar cells (PSCs) are two promising photovoltaic techniques for next‐generation energy conversion devices. The rapid increase in the power conversion efficiency (PCE) in OSCs and PSCs has profited from synergetic progresses in rational material synthesis for photoactive layers, device processing, and interface engineering. Interface properties in these two types of devices play a critical role in dictating the processes of charge extraction, surface trap passivation, and interfacial recombination. Therefore, there have been great efforts directed to improving the solar cell performance and device stability in terms of interface modification. Here, recent progress in interfacial doping with biopolymers and ionic salts to modulate the cathode interface properties in OSCs is reviewed. For the anode interface modification, recent strategies of improving the surface properties in widely used PEDOT:PSS for narrowband OSCs or replacing it by novel organic conjugated materials will be touched upon. Several recent approaches are also in focus to deal with interfacial traps and surface passivation in emerging PSCs. Finally, the current challenges and possible directions for the efforts toward further boosts of PCEs and stability via interface engineering are discussed.

Synergistic Interface Energy Band Alignment Optimization and Defect Passivation toward Efficient and Simple‐Structured Perovskite Solar Cell

“…In the last decade, perovskite solar cells (PSCs) have attracted great attention with their unparalleled increase of power conversion efficiency (PCE) from the initial 3.8% to the current record of 25.2% by virtue of intensive materials and interface engineering . The excellent ambipolar charge transport properties of perovskite family as well as the complex and energy intensive electron transport layer (ETL) and its associated UV‐light instability of the whole device soon lead to the invention of ETL‐free PSCs with much simplified structure, reduced processing steps, and lower production cost, hence great potential in large‐area flexible application .…”

Secondary Bonds Modifying Conjugate‐Blocked Linkages of Biomass‐Derived Lignin to Form Electron Transfer 3D Networks for Efficiency Exceeding 16% Nonfullerene Organic Solar Cells

“…[ 1–6 ] So far, the champion power conversion efficiencies (PCEs) of single‐junction and tandem NFAs‐OSCs approach 17.4% and 17.3% with optimized devices, as well as in‐depth understanding on the interfacial modification. [ 7,8 ] However, the traditional interfacial materials, working effectively for fullerene based OSCs, are ineffective for the NFAs‐OSCs due to the impeded electron transfer in all directions of NFAs' conformational anisotropy. [ 8 ] In this regard, it is the highly desirable to explore novel interfacial materials with effective electron transfer and collection for high‐performance NFAs‐OSCs.…”

“…[ 7,8 ] However, the traditional interfacial materials, working effectively for fullerene based OSCs, are ineffective for the NFAs‐OSCs due to the impeded electron transfer in all directions of NFAs' conformational anisotropy. [ 8 ] In this regard, it is the highly desirable to explore novel interfacial materials with effective electron transfer and collection for high‐performance NFAs‐OSCs.…”

The Energy‐Alignment Engineering in Polytriphenylamines‐Based Hole Transport Polymers Realizes Low Energy Loss and High Efficiency for All‐Inorganic Perovskite Solar Cells

“…Among these all‐inorganic PVSCs, either the very large band gap of CsPbBr 3 or the structurally low stability of CsPbI 3 inhibited their further development . To address this disadvantage, the structurally more stable CsPbI 2 Br was created and studied tremendously.…”