MBE-Grown GaAsSb Nanowire-Based Core Shell n-i-p Heterojunction Photodetector up to 1.5 micrometers
Abstract
In the past few years, GaAs1-xSbx nanowire (NW) has attracted tremendous attention for the near-infrared photodetector (NIRPD) applications, as it covers important telecommunication wavelengths (1.3 m and 1.55 m). This dissertation reports on the successful fabrication of high-performance core-shell (C-S) n-i-p heterojunction-based GaAsSb NWs on n-Si (111). For realizing advanced high-performance NW-based IRPD, the assessment of dopant incorporation is essential. Therefore, we investigated on the variation in carrier concentration of Te-doped GaAsSb NWs and Be-doped GaAs NWs as a function of GaTe and Be cell temperatures using a combination of contactless, non-destructive techniques X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), conductive-atomic force microscopy (C-AFM), and scanning Kelvin probe microscopy (SKPM). C-S n-i-p GaAsSb NWs provide an ideal platform for the high-performance NIRPD. Therefore, a systematic and detailed device study has been carried out to design different C-S architectures to improve device performance and increase the cutoff wavelength. These studies have successfully led to the growth of C-S n-i-p GaAsSb NWs with a high responsivity of 190 A/W and detectivity of 1.1 x 1014 Jones at -1V bias up at the wavelength of 1.1 m. However, to further redshift the device operational wavelength, a novel hybrid axial C-S n-i-p GaAsSb PD has been bandgap engineered with higher Sb% (GaAs0.70Sb0.30), which exhibits responsivity of 18 A/W and detectivity of 1.1 x 1013 Jones extending up to 1.5 m. The successful demonstration of room temperature hybrid axial C-S n-i-p GaAsSb NWs NIRPD thus paves the way to realize high-performance PD beyond 1.5 m, and the novel design structure can expand to other designs that have not been conceived yet for the next-generation optoelectronic devices.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 03, 2022
- Accession Number
- AD1223742
Entities
People
- Priyanka Ramaswamy
Organizations
- North Carolina Agricultural and Technical State University