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We report on the fabrication of p-Si/n-CdO and p-Si/n-CdIn2O4 junction diodes using chemically prepared pure CdO and In 5–20 wt.%-doped CdO nanoparticles. The cadmium oxide (CdO) and indium-doped cadmium oxide (ICO) nanoparticles were characterized using x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, energy dispersive analysis, high-resolution transmission electron microscopy (HRTEM), UV-Vis analysis, photoluminescence (PL) and electrical conductivity measurements. The strongest orientation along the (111) plane for CdO indicates a fcc crystal system. The average particle size of ICO nanoparticles vary from 26 nm to 41 nm. The FTIR bands for ICO samples at 508–511 cm−1 was strongly remodeled while increasing the doping concentration of In at 15 wt.%. HRTEM revealed a clear spherical morphology ~16.28 nm of average particle size for the ICO with 20 wt.% In. Moreover, a maximum electrical conductivity of 15.084 × 10−10 S cm−1 with higher transmittance range of about 76.11% was achieved. The photosensitivity of the p-Si/n-CdIn2O4 diode varied from 103 to 104 %. Also, high quantum efficiency ~225.92% and specific detectivity 5.1952×1011 Jones were found for p-Si/n-CdIn2O4 photodiode. These outcomes suggest that the developed p-Si/n-CdIn2O4 diode is suitable one in the fabrication of UV photodetector and solar cell devices for electronic communication. [ABSTRACT FROM AUTHOR]

The growth behavior of pure and Sr included HfO2 composite thin films for different concentrations of Sr (5, 10, and 15 Wt%) through the Jet Nebulizer Spray Pyrolysis technique is discussed in detail. The preparation of Al/HfO2/n-Si and Al/Sr:HfO2/n-Si Schottky barrier diodes and their rectification behavior were compared. The appearance of intermediate (Sr2HfO4) and new (SrO2) phases upon introduction of Sr in HfO2 was recorded through XRD analysis, and particle size enlargement was observed. The absorption coefficients and bandgap energies of pure and Sr included HfO2 films were determined using UV-VIS analysis, and the results imply that the presence of Sr2HfO4 in Sr:HfO2 increases the overall bandgap from 3.8 to 4.0 eV. The morphology of pure HfO2 was heavily influenced by the presence of Sr; FESEM micrographs revealed that the self-assembled sphere like structure of HfO2 turned into mixed morphology like the rod shape of SrO2 and the contorted spheres of Sr2HfO4. EDAX elementary studies have confirmed the presence and percentage changes of Sr, Hf, and O in pure and Sr included composites thin films. The XPS spectrum has confirmed Sr in SrO2 and Sr2HfO4 phases, and its oxidation states in different phases were verified using short XPS scans. The I–V curves of pure (Al/HfO2/n-Si) and Sr:HfO2 composite (Al/Sr–HfO2/n-Si) diodes were studied and compared. The 15% Sr included HfO2 showed higher rectification behavior when compared with pure Al/HfO2/n-Si and composited (5 and 10%) Al/Sr–HfO2/n-Si at room temperature. [ABSTRACT FROM AUTHOR]

• Novel high-performance p-CuO@CuS/n-Si photodetectors have been facilely fabricated. • Structural and vibrational studied confirm the synthesis of fabrication of CuO@CuS nanocomposite system. • Core-shell structure like morphology was approved by FESEM & HRTEM analyses. • High P s of ∼ 7.76 104 % & R ∼ 798.61mA/W was observed for the fabricated photodetector. • High detectivity (D*) of 8.19 ×1011 J & of ∼ 309.66%, was observed for the fabricated photodetector. Development of photo detectors based on different semiconducting materials with high performance has been in progress in recent past, however, there is a lot of difficulties in developing the more effective photo detectors-based devices with high responsivity, detectivity and quantum efficiency. Hence, we have synthesized pure CuS and CuO@CuS core-shell heterostructure based photo detectors with high performance by simple and cost-effective two-step chemical co-precipitation method. The phase purity of CuS and CuO@CuS composite was observed by XRD analysis and the result were verified with Raman spectroscopy studies. Sphere like morphology of pure CuS and core-shell structure formation of CuO@CuS are observed with scanning and transmission electron microscopes. The presence of expected elements has been confirmed with EDX elemental mapping. Light harvesting photodiodes were fabricated by using n-type silicon substrate through drop cost method. Photo sensitive parameters of fabricated diodes were analyzed by I–V characteristics. The p-CuO@CuS (1:1)/n-Si diode owned a maximum photosensitivity (Ps) ∼ 7.76 × 104 %, photoresponsivity (R) ∼ 798.61 mA/W, external quantum efficiency (E Q E)∼309.66 % and specific detectivity (D*) ∼ 8.19 × 1011 Jones when compared to p-CuS/n-Si diode. The obtained results revealed that the core/shell heterostructure of CuO@CuS is the most appropriate for photo detection. [ABSTRACT FROM AUTHOR]

Novel nanostructure formations like core-shell influence the sensing nature of the optoelectronic devices. In this report, transition metal oxides (TMOs) and transition metal dichalcogens (TMDCs) based sensing layer fabrication and their influence in photo sensing performances were analysed. The metastable h-MoO 3 , thermally stable α-MoO 3 , as synthesized MoS 2 and combinational MoO 3 @MoS 2 core@shell nanocomposites are synthesized by co-precipitation method. Phase purity of synthesized particles was analysed with XRD. Vibration modes of the samples were confirmed with Raman spectroscopy. The morphology behaviours of MoO 3 in different polymorphs due to annealing temperature namely prismatic like h-MoO 3 , layered rod like α-MoO 3 and sphere like MoS 2 decorated core@shell MoO 3 @MoS 2 were observed in the FE-SEM micrographs. The core@shell rod like structured was recorded with HRTEM. Further construction of photodiodes such as n-(h-MoO 3)/p-Si, n-(α-MoO 3)/p-Si, n-MoS 2 /p-Si and n-MoO 3 @MoS 2 /p-Si by employing solution processed method with pre-synthesized particles were discussed in detail. The current-voltage (I–V) characteristics and photo sensing parameters of detector are compared. From the experimental result, n-MoO 3 @MoS 2 /p-Si has better photosensitivity (P S) of 21678.6 (%) and the specific detectivity (D*) of 5.813 × 1010 Jones. [Display omitted] • Novel n-MoO 3 @MoS 2 /p-Si heterostructure diode has been facilely developed. • Structural and vibrational studied confirm the fabrication of n-MoO 3 @MoS 2 system. • MoS 2 decorated core@shell MoO 3 @MoS 2 was observed in the FE-SEM micrographs and core@shell rod like structured were recorded with HRTEM. • The development of photodiodes such as n-(h-MoO 3)/p-Si, n-(α-MoO 3)/p-Si,n-MoS 2 /p-Si and n-MoO 3 @MoS 2 /p-Si has been done. • n-MoO 3 @MoS 2 /p-Si shows (P S) of 18659 (%) and the (D*) of 5.813 × 1010 Jones. [ABSTRACT FROM AUTHOR]

In this work, boron doped graphene nanoparticles (NPs) were synthesized by the hydrothermal route with different boron tribromide concentrations such as 52, 104, and 156 μL. The structural, morphological and optical properties of the prepared NPs were studied using different characterization techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), atomic force microscopy (AFM), UV–vis spectroscopy and photoluminescence spectroscopy (PL). The XRD pattern reveals the hexagonal crystal structure. The SEM image showed textured sheet-like layers which got agglomerated to form fluffy structures. The TEM images recorded single-crystalline nature and also confirms the particle size was reduced upon increasing boron tribromide solution concentration with recognizable particle shape. The topographic properties of the synthesized B-doped graphene NPs were also studied through AFM images. The UV visible absorbance characteristics peaks 243 and 372 nm were observed correspond to π – π* in C–C bands and n- π* transition. After that as grown NPs were used to fabricate diode junctions on p-Si substrates (p-Si/n-B-doped graphene). The electrical performance of each p-Si/n-B-doped graphene diodes junction was examined using I–V characteristics and electrical parameters of diode junction such as ideality factor, barrier height and reverse saturation current were found 2.9–4.3, 0.75–0.83 eV and 4.88 × 10−6-7.26 × 10−6 A. The calculated ideality factor values of the p-Si/n-B-doped graphene diodes are decreased with increase in boron tribromide solution concentration. [Display omitted] • Boron doped graphene nanoparticles were synthesized by the hydrothermal route for various concentrations of Boron tribromide. • XRD pattern exhibited a hexagonal crystal structure with sharp crystalline peak at (002) orientation. • A sheet-like surface morphology was observed through SEM image. • TEM images confirm the particle size was reduced upon increasing boron tribromide. • A minimum ideality factor of n = 2.9 was obtained for p-Si/n-B-doped Graphene diode fabricated with 156 μL. [ABSTRACT FROM AUTHOR]