Xiaoyao Chen

Study on noise behaviors of epitaxial Si:P blocked-impurity-band detectors

The noise behaviors of the epitaxial Si:P BIB detectors have been investigated by experimental and theoretical tools. The device structure and testing system are presented in detail. The relationship between the noise spectral density and device temperature is analyzed. It is demonstrated that not only thermal noise but also shot noise are strongly dependent on the device temperature.

Design consideration for ion-implanted planar GaAs blocked-impurity-band detectors

Design of ion implantation scheme for the planar GaAs blocked-impurity-band (BIB) detectors is performed by numerical simulation. The device structure and the preparation process are presented. It is demonstrated that the implanted Si ion concentration of the absorbing region and the contact region are 5×10¹⁵ cm^-3 and 4×10¹⁹ cm^-3, respectively, and can be implemented by four-step implantation with different ion energies and doses.

The dependence of dark current on temperature in epitaxial Si:P BIB detector

The dependence of dark current on temperature has been investigated for epitaxial Si:P blocked-impurity-band (BIB) detector. For this purpose, an experimental testing system was constructed. The dark-current behavior of epitaxial Si:P BIB detector in the temperature range from 9.2K to 24.3K and the bias range from -3V to 3V has been obtained. It is shown that the detector exhibits low dark current at the bias voltage of 0.2V and temperature below 20K.

Opto-electrical characteristics of Si-based blocked-impurity-band detector: Experiment and simulation

Opto-electrical characteristics of Si-based blocked-impurity-band (BIB) detector are investigated by combing experiment with simulation. The measured black-body response characteristics at different temperature are discussed. The simulated dark current characteristics with different thicknesses of blocking layer are also presented by taking into account impurity-band effects.

A novel plasmonic nanosensor based on electro-magnetically induced transparency of waveguide resonator systems

We propose a plasmonic refractive index-sensitive nanosensor based on the electromagnetically induced transparency (EIT) of waveguide resonator systems. The structure consists of one tooth-shaped cavity as well as the bus and stub metal-insulator-metal waveguides. By adjusting the structural geometry, it is demonstrated that the controllable transmission of EIT response can be obtained with the finite-difference-time-domain simulations. It is found that the transmission spectra dip can be strongly controlled by changing the refractive index filled in the stub waveguide. The calculated results show that the sensitivity of the plasmonic nanosensor is 733 nm/RIU.

Photoresponse simulation for separate absorption and multiplication GaN/AlGaN avalanche photodiode

We present the detailed procedure for modeling of separate absorption and multiplication (SAM) GaN/AlGaN avalanche photodiode (APD). The bias-dependent spectral responsivity characteristics are obtained by using the constructed two-dimensional numerical model. It is found that the spectral responsivities with wavelength from 240 to 450nm are entirely increased with the increased bias.

Electrical characteristics simulation of GaAs-based blocked-impurity-band detector for THz application

Electrical characteristics of GaAs-based blocked-impurity-band (BIB) detector are numerically studied. Electron density and electric field distributions of the device are presented with consideration of immaturity of GaAs blocking layer. Temperature-dependent dark current characteristics are then simulated by taking into account impurity-band effects.