Solution‐Processed Ternary Oxides as Carrier Transport/Injection Layers in Optoelectronics

Abstract

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.

Tin Oxide Electron‐Selective Layers for Efficient, Stable, and Scalable Perovskite Solar Cells

“…On the device level, the light-harvesting efficiency can also be affected by the optical properties of these layers, especially those facing sunward (e.g., ESL in the n-i-p configuration). Table 1 gives a summarized comparison of SnO 2 with state-of-the-art ESLs, [34,46,[55][56][57][58] which we discuss next in greater detail, with a focus on the n-i-p configuration.…”

“…To date, numerous materials have already been studied to possibly replace the c-TiO 2 /m-TiO 2 stack in PSCs; most of them are metal oxides such as SnO 2 , ZnO, Nb 2 O 5 , Zn 2 SnO 4 , SrTiO 3 , BaSnO 3 , CoO x , In 2 O 3 , and WO x , but also other material systems have been evaluated such as phenyl-C 61 -butyric acid methyl ester (PCBM), C 60 , and CdS. [28][29][30][31][32][33][34][35] Among all these materials, SnO 2 stands out as particularly promising due to its combination of desirable features such as a wide bandgap with high optical transmittance in the visible range, a high electron mobility, low conduction band (CB) offsets with commonly used perovskite absorbers, and decent chemical stability. In 2015, low-temperature-processed (≤200 °C) SnO 2 -based PSCs were introduced by Ke et al, with a champion PCE of 17.2% [36] (see Scheme 1 and Figure 1).…”

High‐Performance Quantum‐Dot Light‐Emitting Diodes Using NiOx Hole‐Injection Layers with a High and Stable Work Function

“…Solution‐processed oxides provide a unique combination of rich and tunable optoelectronic properties and excellent stability, making them attractive as charge‐injection/charge‐transporting materials in optoelectronic devices . For example, NiO x is an intrinsic p‐type oxide semiconductor.…”

Indoor Organic Photovoltaics: Optimal Cell Design Principles with Synergistic Parasitic Resistance and Optical Modulation Effect

“…A widely used HTL material for OPVs is poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). [71,72] The unique optical and electrical features of PEDOT:PSS such as high hole mobility, high work function, high transparency in the visible region, tunable conductivity, and low-temperature processability make it particularly suitable for the HTL of outdoor OPVs. However, it has some intrinsic drawbacks for indoor OPVs, such as high acidity (causing low reliability) and insufficient electron affinity (inducing poor electron-blocking property).…”