Electrical properties of short period InAs/GaSb superlattice

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Midwave infrared InAs/GaSb superlattice photodiode with a dopant-free p–n junction

Midwave infrared (MWIR) InAs/GaSb superlattice (SL) photodiode with a dopant-free p–n junction was fabricated by molecular beam epitaxy on GaSb substrate. Depending on the thickness ratio between InAs and GaSb layers in the SL period, the residual background carriers of this adjustable material can be either n-type or p-type. Using this flexibility in residual doping of the SL material, the p–n junction of the device is made with different non-intentionally doped (nid) SL structures. The SL photodiode processed shows a cut-off wavelength at 4.65 μm at 77 K, residual carrier concentration equal to 1.75 × 1015 cm−3, dark current density as low as 2.8 × 10−8 A/cm2 at 50 mV reverse bias and R0A product as high as 2 × 106 Ω cm2. The results obtained demonstrate the possibility to fabricate a SL pin photodiode without intentional doping the pn junction

The economic value of kenaf

Kenaf [Hibiscus cannabinus] należy do rodziny Malwaceae. Pochodzi z tropikalnych i subtropikalnych regionów Afryki i Azji. Od ponad 4000 lat uprawiany w celu pozyskania włókna, pożywienia i opału. Po II wojnie światowej w USA rozpoczęto badania z kenafem, jako obiecującym, jednorocznym surowcem do produkcji papieru. Ostatnio również w Europie zainteresowano się kenafem, jako rośliną dającą wysoki plon biomasy (do 26 t/ha), z ciągle rosnącym zastosowaniem w przemyśle. W 2006 r. w Pętkowie (woj. wielkopolskie) założono doświadczenie polowe w celu poznania możliwości plonowania kenafu w polskich warunkach klimatyczno-glebowych i porównania z konopiami włóknistymi. Zastosowano 5 różnych gęstości siewu, określono plon biomasy i zawartość włókna. Kenaf uprawiany na poletkach doświadczalnych w Pętkowie osiągnął plon biomasy porównywalny z plonem konopi włóknistych. Jednakże do dalszych prac doświadczalno-wdrożeniowych na terenie Polski należałoby sprowadzić nasiona odmian o krótszym okresie wegetacji.Kenaf (Hibiscus cannabinus) belonging to Malvaceae family, originates from tropical regions of Africa and Asia. It has been cultivated since above 4000 years for getting fibre, food and fuel. After world war 2nd the experiments with kenaf were undertaken in the USA, as a promising one-year raw material for paper production. Recently yhe interest in kenaf is observed in Europe, as a plant giving high biomass yields (up to 26 t/ha), with still increasing list of its applications in the industry. In 2006, at Pętkowo Experimental Station (Wielkopolskie province), a field experiment has been arranged in order to recognize the yielding potential of kenaf under Polish climate and soil conditions, and to compare it with the fibrous hemp. At five different sowing densities the biomass yields and fibre contents were determined. Kenaf cultivated on experimental plots at Pętkowo achieved biomass yield comparable to the yield of the fibrous hemp. However, in further experimental and implementation works on terrains of Poland, the seeds of cultivars characterized by shorter vegetation period should be applied

Effect of pressure on electrical properties of short period InAs/GaSb superlattice

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