Photo-Sensitivity and Charge Transport in Novel Narrow-Bandgap Semiconductors for Single THz Photon and Dark Matter Detection

Efficient detection of single THz photons is an outstanding challenge in the fields of particle astrophysics and THz spectroscopy that would open new pathways for dark matter discovery. While single THz photon counting has been achieved with quantum dot sensors, these devices suffer from an inability to resolve the energy of individual photons. Highly pure narrow bandgap semiconductors have emerged as natural candidates for single THz energy resolvable detectors. In this talk we discuss the photosensitivity and subsequent photo-electron transport properties in a series of novel narrow bandgap materials that we have synthesized with bandgaps on the order of 10-100 meV. Resistivity measurements indicate that these candidate materials have lower dark count rates than existing photodetectors in this energy range. We further discuss how we are developing these materials into detectors to be used in the search for low mass dark matter using cryogenic based charge amplification techniques.