Red-Emitting Semiconductor Quantum Dot Lasers

Abstract

Visible-stimulated emission in a semiconductor quantum dot (QD) laser structure has been demonstrated. Red-emitting, self-assembled QDs of highly strained InAlAs have been grown by molecular beam epitaxy on a GaAs substrate. Carriers injected electrically from the doped regions of a separate confinement heterostructure thermalized efficiently into the zero-dimensional QD states, and stimulated emission at approximately 707 nanometers was observed at 77 kelvin with a threshold current of 175 milliamperes for a 60-micrometer by 400-micrometer broad area laser. An external efficiency of approximately 8.5 percent at low temperature and a peak power greater than 200 milliwatts demonstrate the good size distribution and high gain in these high-quality QDs.

Photoluminescence study of InAs quantum dots embedded in GaNAs strain compensating layer grown by metalorganic-molecular-beam epitaxy

“…Thus, improvement of QD lasers will depend on further investigations of increasing the QD density and controlling the size distribution. 12 It has been extensively studied on the dot density and size uniformity of QDs. The well-resolved excited-state peaks of quantum dots have been observed in PL spectra with improvement of the dot size homogeneity for lower QD density.…”

Synthesis, Self-assembly and Optoelectronic Properties of Monodisperse ZnO Quantum Dots

“…Meulenkamp has reported a synthetic process with the highest temperature at only room temperature to make as-prepared ZnO QDs at a size of 3-6nm [29]. In typical preparation of ZnO QDs, zinc acetate dehydrate (Zn(CH 3 COO) 2 ·2H 2 O) or purity zinc acetate (Zn(CH 3 COO) 2 ) was mostly chosen as Zn precursor, while it is much more flexible to choose other reagents as oxygen source, such as lithium hydroxide (LiOH) [4][5][6][7][8], sodium hydroxide (NaOH) [9][10][11][12][13], Monoethanolamine (MEA) [14,15], Diethylene Glycol (99.5% DEG, ethylenediamine-tetra-acetic acid (EDTA)) [16,17], Triethanolamine (TEA) [18] and water [19,20]. Various alcohols like ethanol [4-8,12,14,], propanol [9][10][11][12][13]19,20] were used as solvents.…”

“…Applications of QDs on biology, photovoltaic devices, solar cells, sensors and QD-LEDs also have gained great interest in their relative research fields [3][4][5][6][7]. Much effort has been devoted to fabricating and developing compound semiconductor QDs, such as CdSe, CdTe, GaAs, InAs, InP, ZnS and ZnO [8][9][10][11][12][13][14].…”

Dislocation-induced spatial ordering of InAs quantum dots: Effects on optical properties

“…1,2 Several emerging device applications, such as lasers, detectors, and memories, using QDs have encouraged these efforts. [3][4][5] During the self-assembled growth on planar substrates, quantum dots arrange themselves in a random manner. While this is acceptable for some QD applications, control of the position and ordered QD configurations will enable other types of applications and offer new functions for QD devices, like new highly parallel computing architectures 6 and single electron transistors.…”