Demonstration of a Room-Temperature InP-Based Photodetector Operating Beyond 3 $\mu$ m

An InP-based p-i-n photodiode with optical response out to 3.4
$\mu\hbox{m}$
was designed and grown by molecular beam epitaxy (MBE). One hundred pairs of 7-nm
$\hbox{In}_{0.34}\hbox{Ga}_{0.66}\hbox{As}$
/5-nm
$\hbox{GaAs}_{0.25}\hbox{Sb}_{0.75}$
quantum wells strain compensated to InP were used as the absorption region. The device showed a dark current density of 9.6 mA/cm
$^{2}$
under
$-$
0.5-V reverse bias, a responsivity of 0.03 A/W, and a detectivity of
$2.0\times 10^{8}\ \hbox{cm}\cdot\hbox{Hz}^{1/2}\cdot\hbox{W}^{-1}$
at 3
$\mu\hbox{m}$
at 290 K.