Valence band offset in heterojunctions between crystalline silicon and amorphous silicon (sub)oxides (a-SiOx:H, 0<x<2)
نویسندگان
چکیده
The heterojunction between amorphous silicon (sub)oxides (a-SiOx:H, 0 4 eV for the a-SiO2/c-Si interface, while the electronic quality of the heterointerface deteriorates. High-bandgap a-SiOx:H is therefore unsuitable for the hole contact in heterojunction solar cells, due to electronic transport hindrance resulting from the large ∆EV. Our method is readily applicable to other heterojunctions.
منابع مشابه
Valence band alignment and hole transport in amorphous/crystalline silicon heterojunction solar cells
To investigate the hole transport across amorphous/crystalline silicon heterojunctions, solar cells with varying band offsets were fabricated using amorphous silicon suboxide films. The suboxides enable good passivation if covered by a doped amorphous silicon layer. Increasing valence band offsets yield rising hole transport barriers and reduced device effciencies. Carrier transport by thermal ...
متن کاملBand discontinuities at heterojunctions between crystalline and amorphous silicon
We present a theoretical investigation of the band lineups between crystalline and amorphous silicon, based on the first-principles pseudopotential method and the model-solid theory. We find that the offsets are very sensitive to the hydrogen content of the material; the valence-band offset for a junction with unhydrogenated a-Si is 20.25 eV, while for hydrogenated a-Si with a hydrogen content ...
متن کاملDirect determination of the band offset in ALD-grown ZnO/hydrogenated amorphous silicon heterojunctions from XPS valence band spectra
The chemical composition and band alignment at the heterointerface between ALD-grown zinc oxide (ZnO) and hydrogenated amorphous silicon (a-Si:H) is investigated using monochromatized X-ray photoelectron spectroscopy. A new approach for obtaining the valence band offset EV is developed, which consists in fitting the valence band (VB) spectrum obtained for a-Si:H with a thin ZnO overlayer as th...
متن کاملAmorphous silicon oxide window layers for high-efficiency silicon heterojunction solar cells
Articles you may be interested in Optimized amorphous silicon oxide buffer layers for silicon heterojunction solar cells with microcrystalline silicon oxide contact layers Enhancing the efficiency of SnS solar cells via band-offset engineering with a zinc oxysulfide buffer layer Appl. Analysis of sub-stoichiometric hydrogenated silicon oxide films for surface passivation of crystalline silicon ...
متن کاملFirst-principles study of the valence band offset between silicon and hafnia
Interfaces between silicon and oxides are of great fundamental and technological interest. According to the International Technology Roadmap for Semiconductors, the SiO2-based gate oxide in metal-oxide-semiconductor MOS transistors used in computer processors should be replaced by a higher-K value dielectric material starting in 2008.1 Presently, off-state gate tunneling is increasing power con...
متن کامل