While there are very limited studies of doped ternary metal oxide based hole transport materials, a multifunctional synthesis approach of In doped CuCrO 2 nanoparticles (NPs) as efficient hole transport layers (HTLs) including simplifying the synthesis requirements is proposed, enabling doping and achievement of treatment-free HTLs. Remarkably, compared with conventional methods for synthesizing CuCrO 2 NPs, the newly proposed azeotropic promoted approach dramatically reduces the reaction time by 90% and the calcination temperature by one-third, which not only promotes high throughput production but also reduces power consumption and cost in synthesis. Equally important, indium is successfully doped into CuCrO 2 , which is fundamentally difficult in low temperature processes. The In doping offers less d-d transition of Cr 3+ and p-type doping characteristics for improving HTL transmittance and conductivity, respectively. Interestingly, In doped CuCrO 2 HTL with these improvements can be achieved by a simple ambient-condition process and exhibits thermal stability up to 200 °C, which allows perovskite solar cells (PSCs) to achieve a power conversion efficiency of 20.54%. Meanwhile, the devices show good repeatability and photostability. Consequently, the work contributes to establishing a simple approach to realize pristine and doped multinary oxides based HTL for the development of practical and high performing PSCs.

Colloidal nanocrystals (NCs) with radial-position-controlled doping were synthesized to study the effect of the binding symmetry around Mn2+ dopant. For the four samples ZnSe:Mn/ZnSe, ZnSe/ZnS(2 ML):Mn/ZnS(2 ML), ZnSe/ZnS(1 ML):Mn/ZnS(2 ML), and ZnSe:Mn/ZnS(2 ML), which were in sequence of binding asymmetry around Mn2+ dopant, their photoluminescent (PL) peak showed gradual red-shift (579 to 599 nm) and the PL lifetime became monotonously shorter (0.57 to 0.31 ms), while, as indicated in the electronic paramagnetic resonance spectra, the hyperfine splitting constant became larger (67.9 to 68.4 G) and the g factor became smaller (2.0076 to 2.005). The relation between the luminescent and magnetic properties of the Mn-doped NCs was discussed.

With the remarkable progress in solution‐processed optoelectronics, high performance is required of the carrier transport/injection layer. Ternary oxides containing a variety of crystal structures, and adjustable composition that results in tunable optical and electrical properties, are one of the promising class of candidates to fulfill the requirements of carrier transport/injection layers for high‐performance and stable optoelectronic devices. Solution‐processed ternary oxides have seen considerable progress in recent decades, due to their advantages in the quest to design low‐cost, high‐performance, large‐scale, and stable optoelectronic devices. Herein, the recent advances of solution‐processed ternary oxides are reviewed. The first section consists of a brief introduction to the topic. In the following section, the fundamentals of the effect of tuning ternary oxide composition are summarized. Section three briefly reviews the synthesis approaches for preparing ternary oxides. Section four discusses the recent progress of solution‐processed ternary oxide as carrier transport/injection layer in optoelectronic devices (such as organic solar cells, perovskite solar cells, organic light emitting diodes, etc.). In this section, the impact of controlling ternary oxide composition on device performance and stability is highlighted. Finally, a brief summary and an outlook are given.

As promising photovoltaic devices, perovskite solar cells (PSCs) have attracted extensive and ongoing attention due to easy manufacturing and high power conversion efficiency (PCE). Although the PCE is lower than that of PSCs with normal structure, inverted PSCs have been widely investigated due to their lower hysteresis and potential application. Electron transport layer (ETL) on top of perovskite film in inverted PSCs plays a significant role in device performance. Inorganic top ETL has been used to replace organic ETL for their excellent characters. This review summarizes the progress of inorganic top ETL for high-performance inverted PSCs. Firstly, the principles of top ETL and advantages of inorganic ETL are highlighted. Then the established top ETLs are summarized. Subsequently, various strategies for top ETL fabrication are shown to demonstrate their advantages and shortcomings. Finally, conclusion and outlook of top ETL in inverted PSCs are presented, addressing the issues and directing the hopeful solutions.