To fabricate a thermally stable optical filter in the mid-infrared (MIR) region, a plasmonic metal disk array (PMDA) using tantalum (Ta) was proposed, and the filter performance was compared with that of conventional silver (Ag)-based PMDAs. A finite-difference time-domain method was utilized to systematically analyze the effects of geometric configuration and constituent materials on the optical properties of PMDA filters with a periodic hexagonal lattice. Unlike the Ag PMDA filters, whose transmission dip at resonance wavelengths gradually decreased with increasing temperature, the Ta PMDA filters revealed almost the same transmission spectra even after annealing at 700 °C for 30 min. The Ta-based MIR PMDA filter exhibited similar optical properties to those of the Ag PMDA. The PMDAs with a duty cycle (d.c.) of 60% exhibited stop band spectra with sufficiently deep dip and wide linewidth. MIR filters fabricated with the Ta disks were demonstrated to quantify different types of alcohols through the monitoring of transmission spectra.

For micro-light-emitting diode (LED)-based display applications, such as virtual reality and augmented reality, high-performance Ohmic contacts (namely, the improvement of current injection efficiency) is vital to the realization of high-efficiency micro-LEDs. The surface Fermi level pinning characteristics could be comprehended in terms of the relation between work function of metals (ΦM) and Schottky barrier height (SBH, ΦB). In this study, we have investigated the surface Fermi level pinning characteristics of (001) n-AlInP surfaces by employing Schottky diodes with different metals. With an increase in the temperature, ΦB increases linearly and ideality factors (n) decreases. This behavior is related to the barrier height inhomogeneity. Inhomogeneity-model-based ΦB is evaluated to be in the range of 0.86 – 1.30 eV, which is dependent on the metal work functions and are similar to those measured from capacitance-voltage relation. Further, The S-parameter, the relation between B and M (dB/dM), is 0.36. This is indicative of the partial pinning of the surface Fermi level at the surface states placed at 0.95 eV below the conduction band. Furthermore, it is also shown that (NH4)2S-passivation results in an increases the mean SBH and the S-parameter (e.g., 0.52).