Affiliation:
1. Department of Experimental Physics Wrocław University of Science and Technology Wybrzeże Wyspiańskiego 27 50‐370 Wrocław Poland
2. Department of Semiconductor Materials Engineering Wrocław University of Science and Technology Wybrzeże Wyspiańskiego 27 50‐370 Wrocław Poland
3. Institute of High‐Pressure Physics Polish Academy of Sciences Sokołowska 29/37 01‐142 Warsaw Poland
Abstract
AbstractThe width of polar InGaN quantum wells (QWs) is usually limited to a few nanometers to ensure a sufficient overlap between the wave functions of the ground electron and hole state. This paper presents the results of material gain measurements for thin (2.6 nm), wide (10.4 nm), and extremely wide (25 nm) InGaN QWs. The comparison of experimental data with theoretical predictions allows for correlation of the current density with the carrier concentration, which contributes to the positive material gain, and determination of the coefficients in the standard ABC model. It is shown that the mechanism in wide and narrow polar QWs that leads to electric field screening and lasing is different. For wide QWs, the optical transitions between excited states become dominant in the gain spectrum. The reason for such a gain mechanism is the built‐in electric field, which must first be screened. The ground electron and hole states play a very important role in the screening; however, their contribution to the material gain and lasing in wide QWs is very weak.
Funder
Narodowe Centrum Nauki
Fundacja na rzecz Nauki Polskiej
Narodowe Centrum Badań i Rozwoju