Session Index

"Solution-processed organic-inorganic metal-halide perovskites have been considered as an alternative material for the cost-effective and large-scale manufacturing in variety of optoelectronic devices [1]. Moreover, several advanced researches recently indicate that the perovskites show excellent material properties such as the promising photoluminescence (PL) quantum efficiencies exceeding 70 % and broad emission spectra covering most of the visible range with compositional adjustment, making them feasible for efficient on-chip coherent light-emitting devices [2]. Despite many laser cavities have been proposed to support the lasing action of perovskites from different fabrication processes, for example, crystalline microcavity, nanowire cavity, vertical cavity with both dielectric coated DBRs, and thin film cavity with surface grating, perovskite thin film itself exhibits the random lasing performance even without any resonant cavity. We are the first few groups that demonstrated random lasing behaviors from the solution processed CH3NH3PbI3 thin film at low temperature and reported the phase transition behavior [3]. We also observed the effect of nano-crystalline structures existed in the perovskite thin films on the performance of lasing process [4]. In order to further increase the operation temperature, we applied plasmonic structures on the perovskite thin film to further improve the laser performance by employing the stronger interaction between light and perovskite gain medium [5]. Recently, we exploited the novel solvent-engineered method to make solution-processed methylammonium lead bromide perovskite thin films with excellent optical properties. The random operation can be easily observed at above room temperature condition. Furthermore, with the perovskite synthesized on flexible polyimide (PI) substrates, the lasing performance can be actively controlled via the bending modulation of the supporting substrates, offering a new route to develop the wearable optoelectronic devices. Finally, we applied this random laser light source for the imaging of a simple double-slits system and AF resolution test chart. The acquired low spatial coherence and high contrast-to-noise ratio indicate that such a perovskite thin film random laser can be applied for the advanced speckle-free imaging [6]."

 

We have proposed a highly efficient solution-processed organic light-emitting diode (OLED) with low turn-on voltage based on PEDOT:PSS/TAPC as a hybrid hole injection and electron blocking layer. The best-performing device with the resultant HIL exhibits superior performance (CE=40.1 cd/A, Von=2.7 V) than with PEDOT:PSS (CE=35 cd/A, Von=3 V) at 1000cd/m2

 

In this study, we propose a methodology to enhance the lifetime of flexible organic light-emitting diodes (FOLEDs). By means of improving the encapsulation on FOLEDs, we can increase the efficiency of thermal dissipation. Graphene is the main material to achieve our expected result because of its high thermal conductivity

 

Solar-like light in the wavelength range of 450-650 nm is achieved by LED light source improved by optical filter, which have invert spectrum of the LED light. The filters have about 30 multilayer films fabricated by optical coating. The filtered light has high color rendering rate of 95.6 for D65.

 

In this study, we propose high-performance lead-free perovskite light-emitting diodes based on low-temperature solution-processed lead-free per-ovskites.