Session Index

Membrane-type InGaN micro light-emitting diode with a bottom porous-AlGaN DBR structure has been separated from the sapphire substrate through a chemical lift-off process. The n+-AlGaN:Si/n-AlGaN:Si stack structure has been transformed into the porous-AlGaN/n-AlGaN distributed Bragg reflectors (DBRs) through an electrochemically etching process. The electroluminescence property was observed in the conductive InGaN light-emitting membrane on ITO/glass substrate by using the vertical current injection process.

 

Fabrication of H2S gas sensor on flexible substrates using conventional metal-oxides annealed at over 300oC temperature is not feasible. Here, we have demonstrated SnO2 based NIR- annealed ultra-sensitive H2S gas sensor on food plastic wrap at lower than 50oC as revealed by the thermal imager. The SnO2 film was deposited on plastic wrap by sol-gel process and subsequently annealed by NIR laser (20W/cm2) for 60 seconds. The sensor exhibited the detection limit of H2S gas up to 100 ppb. The NIR power controls the metal-oxide bonds which influence the response of the sensor as suggested by X-ray photoelectron spectroscopy.

 

MoS2 with the superior properties has been extensively investigated as a next generation semiconductor channel material to electronic and optoelectronic devices. We applied the CVD method at argon flow 10 sccm and vulcanization temperature 800 °C to grow MoS2 films. Raman and photoluminescence spectroscopy have confirmed the MoS2 films were trilayer to monolayer.

 

The operational current of an F4-TCNQ doped PTB7 ammonia gas was greatly increased compared with the non-doped PTB7 gas sensor. To understand the mechanism behind the difference of operational current between the two devices, we used space-charge-limited current (SCLC) analysis and UPS measurement to investigate the effects of doping on carrier mobility and the highest occupied molecular orbitals (HOMOs) levels.

  Preview abstract

A method for improving the accuracy of stopping criteria for the broadband optical monitoring for drum-based plasma-assisted reactive magnetron sputtering is proposed. The method used slope of merit function as criteria for terminating deposition to control layer thickness. A five-layer anti-reflection coating was used to verify the proposed method in broadband optical monitoring system.

 

In this work, the films for fabricating Ga2O3-based metal-semiconductor-metal ultraviolet photodetectors were deposited by vapor cooling condensation system. Under bias of 5 V and wavelength of 250 nm, photocurrent, responsivity and detectivity of Ga2O3 MSM-PDs in parallel structure were 2.10 nA, 0.16 A/W and 7.5 × 1011 cmHz0.5W-1, respectively.

 

In this work, we report our implementation of high speed THz spatial light modulator using organic semiconductor. The material is fabricated by modifying a well-known photocatalyst material, graphitic carbon nitride (g-C3N4). We conducted characterization on the modulation depth, carrier lifetime of the sample. From the results, maximum modulation depth of 27.13±0.12% in time domain and 24.55 ± 0.031% is observed, while the carrier lifetime is determined as 4.527 ± 0.178 ns. The results suggest more than 10 folds enhancement compared to gallium arsenide (GaAs), indicating the promising potential of applying modified (g-C3N4) as THz SLMs.

  Preview abstract