Instantaneous decay rate analysis of time resolved photoluminescence (TRPL): Application to nitrides and nitride structures

• Published in: Journal of alloys and compounds 2020-05, Vol.823, p.153791, Article 153791
• Main Authors: Strak, Pawel, Koronski, Kamil, Sakowski, Konrad, Sobczak, Kamil, Borysiuk, Jolanta, Korona, Krzysztof P., Dróżdż, Piotr A., Grzanka, Ewa, Sarzynski, Marcin, Suchocki, Andrzej, Monroy, Eva, Krukowski, Stanislaw, Kaminska, Agata
• Format: Article
• Language: English
• Subjects: Augers; Carrier recombination; Decay rate; Electric fields; Engineering Sciences; Evolution; Low temperature; Multi Quantum Wells; Nitride structure; Nitrides; Optical data processing; Photoluminescence; Physics; Quantum wells; Recombination; Room temperature; Semiconductor; Spectroscopy; Time resolved photoluminescence
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.153791

An analysis of the main recombination modes in nitrides, based on new method of data treatment is proposed for the determination of the carrier recombination processes in optically excited matter measured by time-resolved photoluminescence (PL). The analysis includes basic recombination modes: nonradiative Shockley-Read-Hall (SRH), radiative and Auger recombination in relation to monomolecular, bi-molecular, and tri-molecular processes of optical relaxation. The method is based on the introduction of instantaneous PL decay rate rPL plotted as a function of the PL intensity or of the time. Such an approach provides deep insight into the time evolution of the recombination of the optically excited semiconductor systems and can be applied to the time evolution of a variety of optically excited systems. The demonstration of its strength is given by the application to III-nitride based systems, including nitride highly doped and semi-insulating thick layers, polar and non-polar multi-quantum wells (MQWs). At low temperatures (5 K), the mono- and bi-molecular processes determine the carrier relaxation, and the tri-molecular Auger recombination contribution is negligible. At room temperature the data indicate an important contribution of Auger processes. It is also shown that asymptotic (low excitation), one-exponential recombination rate has different character depending on the presence of the electric fields across the structure. ●We have presented a new method of analysis of TRPL data, based on the instantaneous PL decay rate.●The application of the method is universal.●It could be used to analyze the PL decay kinetics of any system, including semiconducting and molecular structures.●The presented method was used to identify the value of the monomolecular A parameter, and assess the contribution of higher order processes, including Auger recombination in the exemplary non-polar and polar GaN/Al(Ga)N MQW systems.