(1) Stability of Nonfullerene organic solar cells
(2) Visualizing Near-infrared Light
Zhu Furong is a Professor in the Department of Physics, Director for Research Centre of Excellence for Organic Electronics, and Associate Director for Institute of Advanced Materials (IAM) at Hong Kong Baptist University (HKBU). He received his BSc and MSc in Physics from Fudan University, Shanghai China, in 1983 and 1987. He completed his Ph.D in Applied Physics at Charles Darwin University in Australia from 1990-1993. He did his post-doctoral research in the Department of Electrical and Electronic Engineering at Kyoto University in Japan from 1993-1995, and was a Research Fellow with the Department of Physics at Murdoch University in Australia from 1995-1997 working on silicon thin films derived from plasma enhanced chemical vapor deposition for device application. He joined Institute of Materials Research and Engineering (IMRE) in Singapore in 1997. Prior to HKBU, he was a Senior Scientist and a Program Manager leading the organic light-emitting diode (OLED) and organic photovoltaic (OPV) R&D activities at IMRE. His research interests include device physics, surface science, nanostructures and semiconducting materials-oriented research for application in organic semiconductor devices. In 2019, he established a start-up company in Hong Kong, Crimson Vision Technology Limited (宏視科技有限公司). Crimson Vision develops near-infrared visualizing technologies for fast and portable detection.
(1)Stability of Nonfullerene organic solar cells
Remarkable progress has been made in the development of high efficiency solution-processable nonfullerene organic solar cells (OSCs). It shows that a continuous vertical phase separation process occurs in the bulk heterojunction (BHJ) in nonfullerene OSCs, e.g., forming a PBDB-T-rich top surface and an ITIC-rich bottom surface in PBDB-T:ITIC BHJ during the aging period. A gradual decrease in the built-in potential (V0) in the regular configuration PBDB-T:ITIC OSCs, due to the interfacial reaction between PEDOT:PSS hole transporting layer and ITIC acceptor, is one of the reasons responsible for the performance deterioration. The reduction in V0, caused by an inevitable reaction at the ITIC/PEDOT:PSS interface in the nonfullerene OSCs can be suppressed by introducing an MoO3 interfacial passivation layer (Fig. 1). Retaining a stable and high V0 across the BHJ through interfacial modification and device engineering, e.g., as seen in the inverted PBDB-T:ITIC OSCs, is a prerequisite for efficient and stable operation of OSCs].
(2)Visualizing Near-infrared Light
Near infrared (NIR) to visible light up-conversion is of significant importance in many applications including thermal imaging, bio-imaging, night vision and wellness monitoring. This talk will discuss visualizing NIR light via monolithic integration of a charge generation layer (CGL) and a light-emitting diode (LED). The performance of a high performing solution-processable NIR to visible light up-conversion device, comprising a polymer bulk heterojunction (BHJ) NIR CGL and a CsPbBr3 perovskite LED will be presented. An NIR visualizing device, as illustrated in the following figure, provides a platform for NIR imaging applications. The NIR CGL enables an efficient hole injection in the LED in the presence of NIR light, and also serves as an optical out-coupling layer to enhance the visible light emission by the perovskite LED. The perovskite LED has a narrow emission spectrum with a FWHM of 20 nm and a peak wavelength of 520 nm, corresponding to the wavelengths near the peak response of the human eye. Visualizing NIR is demonstrated using different shaped NIR light sources. The up-conversion device can be operated at a low voltage of 3 V. The results are very encouraging, revealing a high performing solution processable up-conversion device for visualizing NIR light.