Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren-Ai Road, Suzhou 215123, People's Republic of China.
Published: May 2019
AI Article Synopsis
Article Abstract
Energy-level alignment at organic-metal interfaces plays a crucial role for the performance of organic electronic devices. However, reliable models to predict energetics at strongly coupled interfaces are still lacking. We elucidate contact formation of 1,2,5,6,9,10-coronenehexone (COHON) to the (1 1 1)-surfaces of coinage metals by means of ultraviolet photoelectron spectroscopy, x-ray photoelectron spectroscopy, the x-ray standing wave technique, and density functional theory calculations. While for low COHON thicknesses, the work-functions of the systems vary considerably, for thicker organic films Fermi-level pinning leads to identical work functions of 5.2 eV for all COHON-covered metals irrespective of the pristine substrate work function and the interfacial interaction strength.
Molybdenum disulfide (MoS) is a notable two-dimensional (2D) transition metal dichalcogenide (TMD) with properties ideal for nanoelectronic and optoelectronic applications. With growing interest in the material, it is critical to understand its layer-number-dependent properties and develop strategies for controlling them. Here, we demonstrate a photo-modulation of MoS flakes and elucidate layer-number-dependent charge transfer behaviors.
Perovskite solar cells (PSCs) have garnered significant attention for their high power conversion efficiency (PCE) and potential for cost-effective, large-scale manufacturing. This comprehensive review focuses on the role of buried interface engineering in enhancing the performance and stability of PSCs with both n-type electron transport layer/perovskite/p-type hole transport layer (n-i-p) and p-type hole transport layer/perovskite/n-type electron transport layer (p-i-n) structures. This study highlights key challenges associated with interface engineering, such as charge extraction, recombination loss, and energy level alignment.
Despite the remarkable advancements in perovskite light-emitting diode (PeLED) technology, the development of blue PeLEDs has lagged. The primary bottleneck lies in the difficulty of finding hole transport materials (HTMs) that can both match the energy levels of blue perovskite materials and exhibit efficient hole transport performance. Herein, a novel non-conjugated polyethylene carbazole-based polymer (P-AGCz) is developed that has excellent solution processability and serves as an efficient dopant-free HTM for PeLEDs.
Carbon-based all-inorganic perovskite solar cells (C-PSCs) are promising alternatives compared with conventional organic-inorganic halide PSCs because of their good thermal stability. However, low carrier transport efficiency and energy level mismatch of the upper interface of the device limit the further improvement of power conversion efficiency (PCE), and all-inorganic perovskites are extremely sensitive to oxygen and humidity, which seriously damages the long-term stability of the device. Upper interface modification is an effective solution to improve the PCE and the stability of devices.
Aromatic linker-constructed self-assembled monolayers (Ar-SAMs) can modulate the work function of indium tin oxide (ITO), thereby improving hole extraction/transport efficiency. However, the specific role of the aromatic linkers between the polycyclic head and the anchoring groups of SAMs in determining the performance of perovskite solar cells (PSCs) remains unclear. In this study, we developed a series of phenothiazine-based Ar-SAMs to investigate how different aromatic linkers could affect molecular stacking, the regulation of substrate work function, and charge carrier dynamics.
