Metamorphic In0.20Ga0.80As p-i-n photodetectors grown on GaAs substrates for near infrared applications

作者：Swaminathan K^*; Yang L M; Grassman T J; Tabares G; Guzman A; Hierro A; Mills M J; Ringel S A

来源：Optics Express, 2011, 19(8): 7280-7288.

DOI：10.1364/OE.19.007280

The growth and performance of top-illuminated metamorphic In0.20Ga0.80As p-i-n photodetectors grown on GaAs substrates using a step-graded Inx(G)a(1-x)As buffer is reported. The p-i-n photodetectors display a low room-temperature reverse bias dark current density of similar to 1.4x10(-7) A/cm(2) at -2 V. Responsivity and specific detectivity values of 0.72 A/W, 2.3x10(12) cm center dot Hz(1/2)/W and 0.69 A/W, 2.2x10(12) cm center dot 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.

• 出版日期2011-4-11