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Contactless Characterization of Carrier Dynamics in Infrared Materials

Arquitola, Amber M
http://orcid.org/0000-0002-0604-1706
http://rave.ohiolink.edu/etdc/view?acc_num=osu1713437537591498

Abstract Details

2024, Doctor of Philosophy, Ohio State University, Electrical and Computer Engineering.
Contactless, nondestructive measurements of minority carrier lifetime by transient microwave reflectance (TMR) and photoluminescence are used to study the carrier dynamics of several ternary materials: InGaAs, GaAsSb, and InAsSb. As contactless measurements, TMR and photoluminescence can determine quality of as-grown wafers. The minority carrier lifetime is inversely proportional to the diffusion component of the dark current and can be used as an indicator of device performance, without the need for full device fabrication. The ability to yield useful information about wafer quality without the time and cost used for fabrication allows for quick feedback to growers. GaAsSb and InGaAs lattice-matched to InP are candidates for short-wave infrared (SWIR) detection at 1.5 μm, a wavelength used for eye safety and optical communication. The high speed or low signal applications at this wavelength benefit from the use of separate absorber, charge, and multiplier (SACM) avalanche photodiodes (APDs). In these devices, the absorber is optimized for detection at the wavelength of interest, and the multiplier is optimized for gain through impact ionization. InGaAs-based SACM APDs are a mature technology and are available commercially. The multipliers paired with InGaAs, however, typically have high noise. Research into low-noise multipliers has resulted in the demonstration of AlGaAsSb as a low noise material. When AlGaAsSb is paired with InGaAs, the grading material AlInGaAs creates a conduction band offset with AlGaAsSb, limiting bandwidth. GaAsSb lattice-matched to InP has similar properties to InGaAs and could be implemented without a conduction band offset due to the grading material being AlGaAsSb. When a GaAsSb/AlGaAsSb SACM APD was demonstrated, it was found to have higher dark current than commercial InGaAs-based devices. Because these materials are so similar, this was unexpected. As mentioned, the diffusion component of the dark current is inversely proportional to the lifetime, and the minority carrier lifetime can be used as a probe of material quality and dark current. Through transient microwave reflectance measurements, it is found that GaAsSb has long low injection lifetimes of greater than 10 μs at several temperatures, indicating that the dark current is not diffusion limited. Evidence of an active Shockley-Read-Hall (SRH)trap is also found, and further study is needed to determine if this trap affects the dark current. Photoluminescence measurements show the measured GaAsSb sample to be of good quality with low disorder. While the measurements of InGaAs and GaAsSb lattice-matched to InP focus on bulk material minority carrier lifetime, the surface lifetime is probed in InAsSb mid-wave infrared (MWIR) nBn structures. It is found through TMR measurements that the introduction of a large number of surface states can produce a detectable change in minority carrier lifetime at high excess carrier densities.
Sanjay Krishna (Advisor)
Steve Ringel (Committee Member)
Preston Webster (Committee Member)
Anant Agarwal (Committee Member)
Shamsul Arafin (Committee Member)
115 p.
Electrical Engineering
GaAsSb on InP; SWIR; minority carrier lifetime; transient microwave reflectance; photoluminescence; InGaAs on InP; material characterization; infrared materials; absorption coefficient; bandgap energy; Urbach energy

Recommended Citations

Citations

  • Arquitola, A. M. (2024). Contactless Characterization of Carrier Dynamics in Infrared Materials [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1713437537591498

    APA Style (7th edition)

  • Arquitola, Amber. Contactless Characterization of Carrier Dynamics in Infrared Materials. 2024. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1713437537591498.

    MLA Style (8th edition)

  • Arquitola, Amber. "Contactless Characterization of Carrier Dynamics in Infrared Materials." Doctoral dissertation, Ohio State University, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=osu1713437537591498

    Chicago Manual of Style (17th edition)

osu1713437537591498
145
© 2024, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.
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