title: Metamorphic In(0.20)Ga(0.80)As p-i-n photodetectors grown on GaAs substrates for near infrared applications.
abstract: The growth and performance of top-illuminated metamorphic In(0.20)Ga(0.80)As p-i-n photodetectors grown on GaAs substrates using a step-graded In(x)Ga(1-x)As buffer is reported. The p-i-n photodetectors display a low room-temperature reverse bias dark current density of ~1.4×10(-7) A/cm(2) at -2 V. Responsivity and specific detectivity values of 0.72 A/W, 2.3×10(12) cm·Hz(1/2)/W and 0.69 A/W, 2.2×10(12) cm·Hz(1/2)/W are achieved for Yb:YAG (1030 nm) and Nd:YAG (1064 nm) laser wavelengths at -2 V, respectively. A high theoretical bandwidth-responsivity product of 0.21 GHz·A/W was estimated at 1064 nm. Device performance metrics for these GaAs substrate-based detectors compare favorably with those based on InP technology due to the close tuning of the detector bandgap to the target wavelengths, despite the presence of a residual threading dislocation density. This work demonstrates the great potential for high performance metamorphic near-infrared InGaAs detectors with optimally tuned bandgaps, which can be grown on GaAs substrates, for a wide variety of applications.
authors.affiliation: Department of Electrical and Computer Engineering, The Ohio State University, 2015 Neil Avenue, Columbus, Ohio 43210, USA.
authors.forename: K
authors.initials: K
authors.lastname: Swaminathan
authors.forename: L-M
authors.initials: LM
authors.lastname: Yang
authors.forename: T J
authors.initials: TJ
authors.lastname: Grassman
authors.forename: G
authors.initials: G
authors.lastname: Tabares
authors.forename: A
authors.initials: A
authors.lastname: Guzman
authors.forename: A
authors.initials: A
authors.lastname: Hierro
authors.forename: M J
authors.initials: MJ
authors.lastname: Mills
authors.forename: S A
authors.initials: SA
authors.lastname: Ringel