Preparation and Deep-UV Solar-Blind Photovoltaic Performance of AlYN-Based MSM Detector

Based on the benefits of AlN solar-blind ultraviolet (SUBV) detectors in the field of photovoltaics, rare Earth element (RE) yttrium (Y) was doped and investigated to regulate the sensitization range of AlN films by dual-target co-sputtering with different Y target sputtering power. The results showed that the structure of the film changed from AlN (002) to a mixture of AlYN (002) and (100) and then to amorphous with increased Y content, accompanied by the transformation from pebble-like shape morphology to amorphous morphology. The adjusted band gap (5.65–4.51 eV) of AlYN films was widened by Y doped, notably, the film S4 (with Y content of 8.1 at.%) completely covered the solar-blind response band. In particular, there were AlYN and Y crystals formed in the film S2 (with Y content of 1.28 at.%) with low resistivity and high carrier mobility. Based on which, metal-semiconductor-metal (MSM) type photodetectors (PDs) with Ag/Al/AlYN MSM interdigitated electrodes (IDE) structures were fabricated, in which the film S2 exhibited the best photo-detection characteristics at −2 V bias, with photo-to-dark current ratio (PDCR), responsivity (R), external quantum efficiency (EQE), and specific detectivity (
${D}^{\ast } $
) of 154.9,
$35.7~\mu $
A/W,
$2.27\times 10^{-{2}}$
%, and
$1.42\times 10^{{10}}$
Jones, respectively, while possessing significant self-powered characteristics (PDCR was 121.5).