Room‐temperature laser operation of a (Ga,In)As/Ga(As,Bi)/(Ga,In)As W‐type laser diode

Abstract

The ongoing pursuit for laser device emitting in the near‐infrared spectral region on GaAs substrates has led to various material systems and device concepts. Alloys containing dilute amounts of Bismuth are promising candidates due to the already substantial band gap shift when incorporating low molar fractions of Bi in the GaAs host lattice. However, devices emitting at technologically essential wavelengths of 1.3 and 1.55 μm have yet to be demonstrated using this material system. Especially the non‐equilibrium nature of the growth conditions required to grow the metastable material makes epitaxial growth with high molar fractions of Bi challenging. An alternate approach to reach the desired wavelengths exploits a type‐II band alignment between two materials to push the emission wavelength further into the telecom bands. Here, room‐temperature laser operation of the first type‐II structure employing Ga(As,Bi) as hole confining layer and (Ga,In)As as electron confining layer is demonstrated. Sample growth is conducted by low‐pressure metalorganic vapour phase epitaxy. Broad area laser devices are processed and characterized by electroluminescence measurements. A threshold current density of 3.86 kA/cm2 and emission wavelength of 1037 nm are observed, showing this device concept's potential for future lasers in the telecom bands.

Systematic strain-induced bandgap tuning in binary III–V semiconductors from density functional theory

“…Semiconductor compounds are central to modern optoelectronics and find applications in various fields, such as solar cells, light-emitting diodes, optical telecommunication, and photovoltaics. [1][2][3][4][5][6][7][8][9][10][11] One of the fundamental properties determining the performance of such optoelectronic devices is the bandgap. The tuning of the size and type of bandgaps is one of the major goals in the field of optoelectronics.…”

“…The most important fundamental property determining these properties is the material's bandgap. For example, materials for optical telecommunication applications require direct bandgaps in the range of 0.80-0.95 eV [3][4][5], while a range of 0.5-2.0 eV is necessary for materials used in efficient solar cells [6][7][8][9]. One material class that is especially versatile in this respect are compound semiconductors, specifically the III-V semiconductors composed of elements from group 13 and 15 of the periodic table of elements [2,5,[10][11][12][13][14][15][16][17][18][19][20][21][22].…”

“…One reason for this lies in the constraints in the growth characteristics of precursor molecules for the chemical vapor deposition techniques often used to grow these materials. Another reason is the thermodynamic instabilities of some elemental compositions [3,14,37,[44][45][46][47][48].…”