 The paper examined the properties of a PIN structure made up of NGASN slash GOS triple quantum well layers. Three different methods were used to evaluate the DLTS spectrum, including a new numerical algorithm. Defects such as material and growth imperfections were identified, along with emission from the quantum well. The energy levels of the structure were calculated and compared. The study concluded that this structure has potential for use in solar cells and suggested further optimization of the growth process. This article was authored by Jakub Rybar, Lubikas Tachlikova, Ladislav Harmatha, and others.