Reduced graphene oxide decorated CuO@NiO nanocomposite and their improved photosensitive activity for photodetection applications.

In our proposed work, pure rGO and CuO@NiO/rGO (CNR) nanocomposites (NCs) with different ratios of CuO@NiO:rGO (90:10, 75:25 and 50:50) were synthesized and explored by XRD, SEM with EDX, TEM, XPS, UV–visible, PL and utilized to measure the current – voltage characteristics under dark and illumination conditions. TEM analysis indicates ultra-thin nanosheets of rGO with lengths of several tens of micrometer and CuO@NiO particle sizes is ∼50 nm. XPS analysis showed the presence of element and chemical states for Cu, Ni, O, and C in CNR-(50:50) sample. The energy gap (E g) of pure rGO is 3.99eV whereas the CNR for 90:10, 75:25 and 50:50 NCs energy gap (E g) values are viz., 1.43eV, 1.41eV and 1.39eV. The diode characteristic of CNR-(50:50)/n-Si exhibit lower ideality factor (n = 1.96), higher barrier height (Φ B = 0.80eV) under illumination condition. The CNR-(50:50)/n-Si photodiode exhibits higher photosensitivity (P S), responsivity (R), External Quantum Efficiency (EQE) and detectivity (D*) values of 956.45 %, 656.29 mA/W, 367.6/1 % and 5.72 × 1012 (Jones) respectively. • rGO/n-Si and CuO@NiO/rGO (CNR) NCs, with ratios CNR-(90:10), (75:25) and (50:50)/n-Si, was synthesized by drop casting method. • The CNR-(50:50)/n-Si exhibits a lower ideality factor (n = 1.96) and higher barrier height (Φ B = 0.80 eV) under 100 mW/cm² illumination. • The CNR-(50:50)/n-Si shows higher P S (956.45%), R (656.29 mA/W), EQE (367.61%) and D⁎ (5.72 × 10¹² Jones) than other photodiodes. [ABSTRACT FROM AUTHOR]