Performance enhancement of inverted perovskite solar cells through interface engineering by TPD based bidentate self-assembled monolayers

WOS:000539377300038Perovskite solar cells (PSCs) have recently appeared as a promising photovoltaic technology and attracted great interest in both photovoltaic industry and academic community. Numerous active researches related to the material processing and operational aspects of device fabrication are under progress since PSCs have a great potential for attaining higher performance compared to that of other solar cell technologies. In particular, interfacial engineering is a crucial issue for obtaining high efficiency in solar cells where perovskite absorber layer is deposited between hole and electron transport layers. In inverted type architecture, PEDOT:PSS is used as both hole transport layer and surface modifier; but unfortunately, this material bears instability due to its acidic nature. Thus, self-assembled monolayers (SAMs) not only are considered as suitable alternative, but also their application is regarded as an efficient and cost effective method to modify electrode surface since it provides a robust and stable surface coverage. In this context, we have employed two novel N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD) based SAM molecules to customize indium tin oxide (ITO) surface in inverted type PSCs. Furthermore, fine-tuning of spacer groups enables us to study device performance depending on molecular structure. This study proposes promising materials for anode interface engineering and provides a feasible approach for production of organic semiconductor based SAMs to achieve high performance PSCs

Molecular engineering-device efficiency relation: Performance boosting of triboelectric nanogenerator through doping of small molecules

WOS:000849663100001Triboelectric nanogenerators (TENGs) are promising new generation systems with their basic motion-based working principle using both triboelectric and electrostatic effects. Today, the energy densities of TENGs are insufficient for many electronic devices and new strategies are needed to increase their power conversion efficiency. In this study, two different Perylene-based organic structures were added to the triboelectric layers as well as the electrochemical properties of these structures, and the device parameters related to these properties were investigated. A large variety of instrumental analyses, including cyclic voltammetry, contact angle, scanning electron microscopy, atomic force microscopy, and so on, have been used to identify the relationship between doped molecules, their doping ratios, and obtained fiber structures. Depending on molecular structure and even any small variations in side groups of molecules, different doping rates brought about various device outputs. Compared with undoped layers, doping of small molecules led to a similar to 3.3 times increase in the maximum power of the best-performed devices, and a very high voltage value of 500 V was obtained. The analysis of doping with small molecules undertaken here has extended our knowledge of how material design improves the electrical output and contributes to the device performance in TENGs