All-epitaxial guided-mode resonance mid-wave infrared detectors
We demonstrate all-epitaxial guided-mode resonance mid-wave infrared (MWIR) type-II superlattice nBn photodetectors. Our detectors consist of a high-index absorber/waveguide layer grown above a heavily doped (n
þþ), and thus, low-index, semiconductor layer, and below a high-index and wide-bandgap grating-patterned layer. Polarization- and angle-dependent detector response is measured experimentally and simulated numerically, showing strongly enhanced absorption, compared to unpatterned detectors, at wavelengths associated with coupling to guided-mode resonances in our fabricated detectors. The detectors show high operating temperature (T ¼ 200 K) external quantum efﬁ- ciencies over 50% for TE-polarized light with absorber thickness of only 250 nm ( ko=20). We calculate T ¼ 200 K estimated speciﬁc detec- tivity for our detectors, on resonance, of 4 10
10 cm Hz1=2 W
1, comparable with state-of-the-art MWIR detectors. The presented results offer an approach to monolithic, all-epitaxial integration of IR detector architectures with resonant optical cavities for enhanced detector response across the mid-wave infrared.