Nanodimensional layers based on polyamic acids and polyamidoimides as protective and passivate coatings in laser AlGaAs/GaAs heterostructures

A study of the application of polyamic acids (PAA) and polyamidoimides (PAI) in manufacturing passivate and protective coatings for the crystal front facet of a semiconductor laser was carried out. The morphology of the surfaces of the deposited films was studied using atomic force microscopy. The structure of the deposited films and their roughness were examined. An analysis of the watt-ampere characteristics of the laser diodes showed that films based on polyamic acids markedly increase the magnitude of the peak power of semiconductor lasers. The highest value of the peak power was obtained for coatings based on polyamic acids instead of polyamidoimides. The value of the peak power for laser structures with a coating based on polyamic acids is 1.3 times higher than for structures without a polymer coating.