Doping and electronic properties of GaAs grown by close-spaced vapor transport from powder sources for scalable III–V photovoltaics

Abstract

We report the use of a simple close-spaced vapor transport technique for the growth of high-quality epitaxial GaAs films using potentially inexpensive GaAs powders as precursors.

The Growing Global Demand for Element Gallium: Electrical and Electronic Waste and Coal Fly Ash as Alternative Sources for its Sustainable Supply

“…Recycling of end-of-life products for recovery of gallium and other critical elements is only at its infancy in developed world with very few reported schemes like Orbite Aluminae Canadian company in Canada and another in central Europe [7,13,27]. This could be due to unprofitability of the exercise as the end-of-life products have not accumulated enough to be able to pay the effort worth it [21].…”

“…Therefore, in total, out of 378t only 47 % was embedded in intermediate and end use products [7]. This underscores the importance of the concept of circular economy that involves recycling of waste and or rejects in form of scrap or wastewater and endof-life products to lessen these loses [2,3,4,13,[19][20][21]30]. This is because unlike in primary production, recovery of Ga from e-waste has efficiencies of up to >95% as shown in table 1 below.…”

“…These applications command high quality [7], as such, impurities are relatively Licensed Under Creative Commons Attribution CC BY low and are likely to be from production methods used. Some reported impurities include oxygen, zinc, tellurium and sulphur [12][13][14] in the purity of over 99.9%. Total gallium concentration in LED devices ranges from 0.001 to 0.005 g/unit [1,15].…”

Epitaxial alloys of AlxGa1−xAs:Mg with different types of conductivity

“…Nevertheless, the annually scalable application of GaAs-nanoheterostructures in optoelectronic devices forced scientists to seek a solution to these old problems and have a fresh look at known classical materials [6][7][8][9][10][11].…”

Эпитаксиальные твердые растворы Al-=SUB=-x-=/SUB=-Ga-=SUB=-1-x-=/SUB=-As : Mg с различным типом проводимости

“…Тем не менее ежегодно наращиваемое исполь-зование GaAs-наногетероструктур в устройствах опто-электроники заставляет исследователей искать решение старых проблем и по-новому взглянуть на классические материалы [6][7][8][9][10][11].…”