TY JOUR TI GROWTH OF LOW DISLOCATION GaN AND AlGaN layers by ammonia mbe KW nitride heterostructures KW AlN KW AlGaN KW UV optoelectronic devices KW microwave transistors KW dislocation density JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Mamaev, V.V. AU Novikov, S.A. AU Petrov, S.I. AU Zaycev, S.V. AU Prohorenkov, D.S. PY 2016 IS 1 PB Belgorod State Technological University named after V.G. Shukhov