Session Index

We have examined the electric field effects on absorption and photoluminescence of lead halide perovskites thin films, quantum dots and two-dimensional quantum wells for the characterization of optical and electronic processes that play important role in photoenergy conversion, and for the detection of information of trap formations and ion migrations.

 

We discussed the enhancement of perovskite films by air quenching method. The perovskite films exhibit high coverage morphology. The current density, open circuit voltage, fill factor and photoelectric conversion efficiency of the solar cell realized by the perovskite films were 25.64 mA/cm2, 0.84 V, 0.67, and 14.48 %, respectively.

 

We investiated optical properties of CsPbBr3 quantum dots with reduced ligand. The PL emission peak reveals blue shift relative to the bulk at 520 nm and fast decay time.Through pump of Q-switched laser, amplified spontaneous emission (ASE) was generated at a relatively low threshold of about 0.19 mJ/cm2

 

We investigated the third-order optical nonlinearity properties in the twodimensional n-butylammonium lead iodide [(BA)2PbI4] perovskite films using Z-scan technique at the pumping wavelength near the band gap of the material. (BA)2PbI4 shows the two photon absorption behavior with the nonlinear absorption coefficient of ~3 cm/MW, and its nonlinear refractive index is estimated to be ~7.1×10-11 cm2/W

 

We intend to develop an optical phase modulation array to manipulate the laser light emissions from the vertical-cavity surface-emitting laser (VCSEL) arrays or photonic-crystal-surface-emitting-laser (PCSEL) diodes as for the three-dimensional sensing applications. The largest beam-steering angle and optimized light-emitting efficiency of metasurfaces are around 35° and 70 %, respectively.

 

This study proposes a novel tilt sensor based on a tapered-shaped polymer with a fiber Fizeau interferometer (TPFFI). Experimental results demonstrate the sensor can measure tilt angles and temperature simultaneously with good sensing characteristics. The measurement sensitivities of tilt angles and temperature are averagely 0.4 dB/deg. and 0.17 nm/°C, respectively.

 

A novel SERS substrate has been developed by electrochemical deposition of silvernano-particles into serrated nano-channels of anodic aluminum oxide (AAO). The branched structure of the silver nano-particles enhances SERS signals of the overlying molecules, which can be used to detect chemicals at lower concentrations.