Bimberg DLedentsov N.NGrundmann MKirstaedter NSchmidt O.GMING-HUA MAOUstinov V.MEgorov A.YuZhukov A.EKopev P.SAlferov Zh.IRuvimov S.SGösele UHeydenreich J.2023-06-092023-06-0919963701972https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030530640&doi=10.1002%2fpssb.2221940116&partnerID=40&md5=5fb803b2b2b48b73d96862af558fd2fdhttps://scholars.lib.ntu.edu.tw/handle/123456789/632397Injection lasers based on InAs-GaAs and InGaAs-GaAs quantum pyramids (QPs) with a lateral size ranging from 80 to 140 Å are realized. The structures with relatively small dots (≈80 Å) exhibit properties predicted earlier for quantum dot (QD) lasers such as low threshold current densities (below 100 A cm-2) and ultrahigh characteristic temperatures (T0 = 350 to 425K). For temperatures of operation above 100 to 130 K T0 decreases and the threshold current density increases (up to 0.95 to 3.3 kA cm-2 at room temperature) due to carrier evaporation from QPs. Larger InAs QPs (≈140 Å) providing better carrier localization exhibit saturation of the ground state emission and enhanced nonradiative recombination rate at high excitation densities. The radiative lifetime shows a weak dependence on the dot size (80 to 110 Å) being close to ≈1.8 to 2 ns, respectively. A significant decrease in radiative lifetime is realized in vertically-coupled quantum dots formed by a QP shape-transformation effect. The final arrangement represents a three-dimensional tetragonal array of InAs islands inserted in a GaAs matrix each composed of several vertically merging InAs parts. The first injection lasing in such an array is achieved.[SDGs]SDG14journal article10.1002/pssb.22219401162-s2.0-0030530640