Effect of contact barrier height on performances of BaSi2 heterojunction and homojunction solar cells

The effects of contact barrier height on performances of Si/BaSi2 p–n heterojunction, BaSi2 p–n homojunction and Si/BaSi2/Si p–i–n heterojunction were numerical calculated. Band energy diagram, built-in electric field, carrier generation and carrier transportation distributed in the devices are comprehensively investigated. BaSi2 p–n homojunction solar cells are very sensitive to front contact barrier height due to the high light absorption coefficient of front p-BaSi2 layer. Si/BaSi2 p–n heterojunction and BaSi2 p–n homojunction solar cells with donor concentration [Formula: see text] less than [Formula: see text] are apparently affected by back contact barrier height. The ideal [Formula: see text]-Si/BaSi2/[Formula: see text]-Si p–n solar cell achieves a high [Formula: see text] of 1.131 V, suggesting a promising and alternative structure to gain excellent BaSi2-based solar cells once the Urbach tail states and defects can be effectively eliminated. The results help to fundamentally understand operation mechanism and provide intuitive guidance for achieving high-efficiency BaSi2 solar cells.

Performance Analysis of TFET and VDSTFET for Low Power Application using the Work Function Engineering

We report a design of TFET which is quite different from conventional TFET. The structure of VTFET is similar to MOSFET but the conducting mechanism is completely different. Vertical TFET is designed perpendicular to the horizontal plane. The switching and carrier transportation mechanism of VTFET is based on the mechanism of the band to band tunneling through a potential barrier and vertical TFET is based on tunneling perpendicular to the device rather than a mechanism like thermionic emission unlike in MOSFET. We have designed a model for the two-dimension structure of V-TFET which consists of the dual-source and single drain. The channel among the drain and gate region is extraordinarily thin. We have plotted the transfer characteristics of V-TFET according to device parameters using TCAD. The comparison of VTFET with DSVTFET is done by using Silvaco TCAD and the effect of source doping, and work function on transfer characteristics of the device is examined by using silvaco TCAD simulations. The proposed device produces a low-off current.

Overcoming Carrier Transport Limitation in Ruddlesden−Popper Perovskite Films by Lamellar Nickel Oxide Substrate

Two-dimensional (2D) Ruddlesden−Popper perovskites films fabricated by solution process are composed of multiple 2D perovskite phases, and carrier transportation is limited by the low-n-value 2D perovskite phases (n=1 and n=2)....

All-inorganic CsPbBr3/GaN hetero-structure for near UV to green band photodetector

Perovskites are promising candidates in photodetectors because of their excellent optical absorption coefficient and long carrier transportation length. However, most perovskites face the great challenge of instability and narrow band...

Influence geometry of the pipeline at the stability of steam-water flow during the exploitation of a geo-power station

Исследуются случаи существования неустойчивости потока, вызванной влиянием гравитационных сил в трубопроводах пароводяной смеси на геотермальных месторождениях. Представлена новая разработанная авторами математическая модель пароводяного течения, учитывающая гравитационный эффект и удовлетворяющая новым вызовам при освоении геотермальных месторождений с двухфазной транспортировкой теплоносителя. Показано влияние наклона трубопровода и рельефа трассы на гравитационную устойчивость течения. Даны рекомендации по гидравлическому расчету и строительству трубопроводов пароводяной смеси. Cases of flow instability caused by the influence of gravitational forces in pipelines of steam-water mixture in geothermal fields are investigated. A new mathematical model of the steam-water flow was developed by authors, taking into account the gravitational effect and satisfying new requirements in the development of geothermal deposits with two-phase heat carrier transportation. The influence of the pipeline incline at the gravitational stability of the flow is shown. Recommendations on hydraulic calculation and construction of steamwater mixture pipelines are given.