Depletion region

About: Depletion region is a research topic. Over the lifetime, 9393 publications have been published within this topic receiving 145633 citations.

Hydrogen plasma treatment of β-Ga2O3: Changes in electrical properties and deep trap spectra

Abstract: The effects of hydrogen plasma treatment of β-Ga2O3 grown by halide vapor phase epitaxy and doped with Si are reported. Samples subjected to H plasma exposure at 330 °C developed a wide (∼2.5 μm-thick) region near the surface, depleted of electrons at room temperature. The thickness of the layer is in reasonable agreement with the estimated hydrogen penetration depth in β-Ga2O3 based on previous deuterium profiling experiments. Admittance spectroscopy and photoinduced current transient spectroscopy measurements place the Fermi level pinning position in the H treated film near Ec-1.05 eV. Annealing at 450 °C decreased the thickness of the depletion layer to 1.3 μm at room temperature and moved the Fermi level pinning position to Ec-0.8 eV. Further annealing at 550 °C almost restored the starting shallow donor concentration and the spectra of deep traps dominated by Ec-0.8 eV and Ec-1.05 eV observed before hydrogen treatment. It is suggested that hydrogen plasma exposure produces surface damage in the near-surface region and passivates or compensates shallow donors.The effects of hydrogen plasma treatment of β-Ga2O3 grown by halide vapor phase epitaxy and doped with Si are reported. Samples subjected to H plasma exposure at 330 °C developed a wide (∼2.5 μm-thick) region near the surface, depleted of electrons at room temperature. The thickness of the layer is in reasonable agreement with the estimated hydrogen penetration depth in β-Ga2O3 based on previous deuterium profiling experiments. Admittance spectroscopy and photoinduced current transient spectroscopy measurements place the Fermi level pinning position in the H treated film near Ec-1.05 eV. Annealing at 450 °C decreased the thickness of the depletion layer to 1.3 μm at room temperature and moved the Fermi level pinning position to Ec-0.8 eV. Further annealing at 550 °C almost restored the starting shallow donor concentration and the spectra of deep traps dominated by Ec-0.8 eV and Ec-1.05 eV observed before hydrogen treatment. It is suggested that hydrogen plasma exposure produces surface damage in the near-...

Recombination in the space-charge region of Schottky barrier solar cells

Abstract: The expression for the recombination rate as a function of voltage, of illumination level, and of position in the space-charge region of the semiconductor is derived analytically. The recombination current density is derived by numerical integration of the above expression. The results show good agreement with experiment for the typical Au- n -type Si near-ideal Schottky barrier solar cells, and the comparison provides information on the uncovering of deep recombination centers by the hole quasi-Fermi level under increasing illumination. It is found that the principal effect of recombination under illumination is the reduction of the photocurrent. A rather surprising but gratifying result is that, once the above effect is taken into account by using short-circuit currents rather than photocurrents, the remaining (voltage dependent) effect of recombination is extremely close to the one in the dark, provided the increase in “uncovered” recombination centers with illumination is taken into account.

High-bias current–voltage–temperature characteristics of undoped rf magnetron sputter deposited boron carbide (B5C)/p-type crystalline silicon heterojunctions

Abstract: The high-bias behaviour of the dark forward and reverse current–voltage (I–V) characteristics of an undoped radio frequency (rf) magnetron sputter deposited boron carbide (p-B5C)/p-type crystalline silicon heterojunction has been investigated at different ambient temperatures (130–300 K). The experimental forward current–voltage–temperature (I–V–T) characteristics indicate that the non-ohmic bulk conduction mechanisms operable in the highly resistive polycrystalline B5C counterpart material of this heterojunction largely determine the behaviour of its forward current at high-bias voltages (>0.3 V). The hopping conduction model of Apsley and Hughes for a flat density of localized energy states (Apsley N and Hughes H P 1975 Phil. Mag. 31 1327) can be utilized to elucidate the bias dependence of the measured heterojunction forward current over an extended bias-voltage range (0.4–2.7 V) at temperatures below 260 K. On the other hand, the junction-like conduction processes occurring in the depletion region should limit the high-bias behaviour of the measured heterojunction reverse current. Bardeen's model for a modified Schottky-like barrier at the p-B5C/p+-Si interface can be satisfactorily applied to describe the reverse current–voltage characteristics at bias voltages larger than 0.4 V.

Silicon carbide MOSFET

Abstract: A silicon carbide MOSFET (10) is formed to have a high breakdown voltage. A breakdown enhancement layer (20) is formed between a channel region (14) and a drift layer (12). The breakdown enhancement layer (20) has a lower doping concentration that increases the width of a depletion region (24) near a gate insulator (17). The increased depletion region width improves the breakdown voltage.