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A heterojunction photodiode was fabricated from Bi doped Cs2SnCl6 nanoparticles (Cs2SnCl6:Bi NPs) spin-coated on an epitaxially grown GaN substrate. With the back illumination configuration, the heterojunction photodiode demonstrated excellent narrow-band UV sensing capability with a full wavelength of half maximum of 18 nm and a maximum detectivity of 1.2 × 1012 jones, which is promising for biomedical applications. In addition to the excellent narrow band UV sensitivity, the device also demonstrated a large linear dynamic range of 71 decibels (dB) and a fast photoresponse speed (a rise time of 0.75 μs and a fall time of 0.91 μs). The excellent performance is attributed to excellent carrier separation efficiency at the heterojunction interface and improved carrier collection efficiency through the multi-walled carbon nanotube (MWCNT) network. All the above advantages are of great importance for commercial deployment of perovskite-based photodetectors. [ABSTRACT FROM AUTHOR]

An ultraviolet (UV) heterojunction photodetector was fabricated from multiwalled carbon nanotubes (MWCNTs)/zinc-oxide nanowires (NWs)/p-GaN composite structure. The photodetector demonstrated significant rectifying characteristics and relative fast transient response with response time on the order of milliseconds. Under back illumination, the photodetector exhibited a narrow bandpass photoresponse spectrum (13-nm full-width at half-maximum) centered at 375 nm with a maximum responsivity of 6 mA/W. The good performance of this heterojunction photodetector is attributed to improved carrier transport and collection efficiency through the MWCNTs network deposited on top of the ZnO NWs. [ABSTRACT FROM PUBLISHER]

A heterojunction photodiode was fabricated from multiwalled carbon nanotubes (MWCNTs)/ZnO nanowires/p-Si (100) substrate composite structure. The heterojunction photodiode demonstrated a faster transient response and higher responsivity than the reference sample without deposition of MWCNTs, which is attributed to improved carrier collection and transport efficiency through the MWCNTs network. The high photoresponsivities of the devices are explained in terms of operation as a hybrid of photodiode and photoconductor modes. The spectral response of the devices showed dependence on voltage polarity and is attributed to the high valance band offset in the interfacial region of ZnO and p-Si substrate. [ABSTRACT FROM AUTHOR]

A heterojunction photodiode was fabricated from ZnO nanowires (NWs) grown on a p-type Si (100) substrate using a hydrothermal method. Post growth hydrogen treatment was used to improve the conductivity of the ZnO NWs. The heterojunction photodiode showed diode characteristics with low reverse saturation current (5.58 × 10-7 A), relatively fast transient response, and high responsivity (22 A/W at 363 nm). Experiments show that the photoresponsivity of the photodiode is dependent on the polarity of the voltages. The photoresponsivity of the device was discussed in terms of the band diagrams of the heterojunction and the carrier diffusion process. [ABSTRACT FROM AUTHOR]