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.

Comparison of Analog Performance of AlN/β-Ga2O3 HEMT by Variation in Dielectric Materials

In the present paper, a high electron mobility transistor based on β-Gα2O3 material (BGO-HEMT) with different dielectrics (Si3N4, Al2O3, and HfO2) at the interface of aluminum nitride (AlN) and the gate is demonstrated. The device has a 10nm AlN layer with 50 nm barrier width, 50nm gate-length, and a value of 5 nm as gate-to-barrier thickness.A highly doped n+ material with a wider gap in between ohmic contact-barrier layers reveals the proposed device's novel traits. The performance is computd in terms of transfer characteristic, transconductance, gate capacitance, 2nd, and 3rd order transconductance values. The proposed structure reduced the dynamic & access resistance and provided a high gm value equal to 0.15S/µm,drain current density value of 650 A/mm (maximum) at Vds= 5 V. In the future, the proposed device can be utilized in high power radio frequency and microwave applications.

TCO and back contact buffer significance to achieve highest open circuit voltage and efficiency of CdTe solar cells

CdTe thin film (TF) solar cells are most promising in commercial stage photovoltaic (PV) technologies. Cell contacts and interface defects related opto-electrical losses are still vital to limit its further technological benefit. Thin film PV cells shallow recombination and parasitic loss lessening purpose carrier selective back contact selection with band matching interface layers are essential. Beside that layer thickness selection is vital for field assisted selective carrier collection. The suitable emitter and buffer layer selection with band gap matching to the active layer can lessen parasitic absorption loss. In this purpose SCAPS software based ZnO and SnO2 TCO as well as CdS and CdSe buffer impact are numerically analyzed. The TCO, emitter, back surface field and metal contacts effects on electrical performance is studied. In the model, TCO and back contact barrier thickness is shown significant to progress electrical performance. Eventually, open circuit voltage Voc = 0.9757 V and 19.92% efficiency is achieved for 90 nm of ZnTe BSF with ZnO TCO and CdS emitter layer of optimized thickness.

The contact barrier of a 1T′/2H MoS2 heterophase bilayer and its modulation by adatom and strain: a first-principles study

The contact nature of the 1T′/2H MoS2 heterophase bilayer is tuned from Schottky to Ohmic by adatom and strain.