Carrier Dynamics in Thin Germanium–Tin Epilayers

Abstract

How to cite:Please refer to published version for the most recent bibliographic citation information. If a published version is known of, the repository item page linked to above, will contain details on accessing it.

High carrier lifetimes in epitaxial germanium–tin/Al(In)As heterostructures with variable tin compositions

“…Carrier lifetimes in Ge 1Ày Sn y materials are expected to increase when grown on latticematched In x Al 1Àx As intermediate buffers, wherein defects and dislocations can be reduced to negligible levels, as opposed to the direct growth of Ge 1Ày Sn y on Si. [40][41][42][43][44][45][46][47][48][49] Lattice-matched Ge 1Ày Sn y /In x Al 1Àx As heterostructures can reduce the defect induced junction leakage and increase the carrier lifetime. Two design strategies are considered here to improve the Ge 1Ày Sn y material quality compared to the direct growth on Si: (a) the thickness of the Ge 1Ày Sn y epilayer on the AlAs/GaAs substrate below the critical layer thickness, and (b) the growth of the Ge 1Ày Sn y epilayer lattice matched to In x Al 1Àx As (no thickness constraints).…”

“…Carrier lifetimes in Ge 1− y Sn y materials are expected to increase when grown on lattice-matched In x Al 1− x As intermediate buffers, wherein defects and dislocations can be reduced to negligible levels, as opposed to the direct growth of Ge 1− y Sn y on Si. 40–49…”

Systematic study on photoexcited carrier dynamics related to defects in GeSn films with low Sn content at room temperature

“…It can be explained that under illumination, EHPs are generated in GeSn. Because the non-radiative recombination process is much faster than the interband recombination process, the carriers are scattered into L valley, SRH centers, or interface/surface states [19]. As a result, the interband emission is suppressed while the trap-related emission is observed.…”

“…The poor-quality GeSn restricts the optical and electrical carrier dynamic in optoelectronic components [9]. For instance, GeSn photodetectors with high Sn contents show high dark leakage current, attributed to the poor material quality and the bandgap shrinking [10].…”

High-performance GE/GESN photodetectors in near- and mid-infrared range

“…Electrically driven carrier dynamics were affected by trap states near the GeSn/Ge interface [151]. Because the nonradiative recombination process is much faster than the interband recombination process, photoexcited carriers are scattered into the L conduction band, SRH centers, or trap states at the interface/surface [152].…”