Peinan Ni

Study of dual color infrared photodetection from n-GaSb/n-InAsSb heterostructures

We report detailed investigation of n-GaSb/n-InAsSb heterostructure photodetectors for infrared photodetection at different temperatures and biases. Our results show that the heterostructure photodetectors are capable of dual color photodetections at a fixed forward bias with its highest responsivity occurred at room temperature; With the decrease of the forward bias, a turning point, at which the photocurrent changes its direction, exist and the corresponding voltage values increases with the decrease of temperature; At all reverse biases, the photocurrents flow in the same direction but the maximum current occurs at about 205 K. A new model is proposed, which can well explain all the observations.

Aluminum based structures for manipulating short visible wavelength in-plane surface plasmon polariton propagation

We report aluminum based structures for manipulation of surface plasmon polariton (SPP) propagation at short wavelength range. Our simulation shows that aluminum is a good metal to excite and propagate SPPs with blue light and that the SPP wavelength can be reduced from about 465 nm to about 265 nm by monitoring the thickness of a coated Si(3)N(4) layer above the aluminum film. It is also shown that the damping becomes more significant with the increase of the thickness of the Si(3)N(4) layer. We also experimentally demonstrated the SPP wavelength tuning effect for 20nm Si(3)N(4) layer covered Al, which can be explained by the variation of effective permittivity. The proposed Metal-Insulator-Air (MIA) structures with SPP wavelength tuning ability have potential applications in 2D optics.

InAs0.91Sb0.09 photoconductor for near and middle infrared photodetection

Antimonide based III–V materials have been attracting great attention as they have wide applications covering photodetection, light source, photovoltaics and electronic devices. In this paper, we report on the structural and optical properties and photodetection performance of an InAsSb layer grown on a GaSb substrate by molecular beam epitaxy (MBE). An x-Ray diffraction (XRD) study shows that the Lattice-mismatch between the GaSb substrate and the InAsSb epitaxial layer is about 0.17% and the derived composition of Sb is about 0.09. Photoluminescence measurements at varied temperatures reveal that the energy band gap of the InAsSb material is about 0.33 eV and the luminescence peaks follow Bose–Einstein relation. The photoconductors fabricated based on the InAsSb/GaSb structure show spectral response ranging from NIR to MWIR range. They can work well at low voltage bias and the measured blackbody detectivitives are ~2.4 × 107 cmHz1/2W−1 and ~6.1 × 109 cmHz1/2W−1 at room temperature and 77 K, respectively.

Antimonide-based semiconductors for optoelectronic devices

We report high quality InAsSb films grown on Ge substrates with a GaAs intermediate layer via metal-organic chemical vapor deposition. The properties of the grown InAsSb films are systematically analysed. It is found that the grown InAsSb films by this method have high quality with very smooth, mirror-like morphology, and high optical quality. In particular, strong PL peak at around 3550 nm can be observed even at room temperature, which demonstrates the capabilities of the grown InAsSb films for room temperature MIR optoelectronic application. This work provides a simple and feasible strategy for the growth of high quality InAsSb films on Ge substrate.