Browsing by Author "Savas, Muzeyyen"

Now showing 1 - 2 of 2

Simple, sustainable fabrication of fully solution-processed, transparent, metal-semiconductormetal photodetectors using a surgical blade as an alternative to conventional tools
(SPIE, 2022) Savas, Muzeyyen; Yazici, Ahmet Faruk; Arslan, Ayenur; Mutlugün, Evren; Erdem, Talha; 0000-0003-0390-1819; 0000-0003-2747-7856; 0000-0003-3715-5594; 0000-0003-3905-376X; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Savas, Muzeyyen; Yazici, Ahmet Faruk; Arslan, Ayenur; Mutlugün, Evren; Erdem, Talha
Fabrication of optoelectronic devices relies on the expensive, energy-consuming conventional tools such as chemical vapor deposition, lithography, and metal evaporation. Furthermore, the films used in these devices are usually deposited at elevated temperatures and under vacuum that impose further restrictions to the device fabrication. Developing an alternative technology would contribute to the efforts on achieving a more sustainable optoelectronics technology. Keeping this focus in our focus, here we present a simple technique to fabricate visible photodetectors. These fully solutionprocessed and transparent metal-semiconductor-metal photodetectors employ silver nanowires (Ag NW) as the transparent electrodes replacing the indium-tin oxide (ITO) commonly used in optoelectronic devices. By repeatedly spin coating Ag NWs on a glass substrate followed by the coating of ZnO nanoparticles, we obtained a highly conductive transparent electrode reaching a sheet resistance of 95 O/? as measured by the four-probe method. Optical spectroscopy revealed that the transmittance of the Ag NW-ZnO films was 84% at 450 nm while transmittance of the ITO films was 90% at same wavelength. Following the formation of the conductive film, we scratched it using a heated surgical blade to open a gap. The scanning electron microscope images indicate that a gap of ~30 mm is opened forming an insulating line. As the active layer, we drop-casted red-emitting CdSe/ZnS core-shell quantum dots (QDs) on to this gap to form a metal-semiconductor-metal photodetector. These visible QD-based photodetectors exhibited responsivities and detectivities up to 8.5 mA/W and 0.95x109 Jones, respectively. These proof-of-concept photodetectors show that the environmentally friendly, low-cost, and energy-saving technique presented here can be an alternative to conventional, more expensive, and energy-hungry techniques while fabricating lightharvesting devices.
Toward sustainable optoelectronics: solution-processed quantum dot photodetector fabrication using a surgical blade
(SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS, 2023) Savas, Muzeyyen; Yazici, Ahmet Faruk; Arslan, Aysenur; Mutlugun, Evren; Erdem, Talha; 0000-0003-0390-1819; 0000-0003-2747-7856; 0000-0003-3715-5594; 0000-0003-3905-376X; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Savas, Muzeyyen; Yazici, Ahmet Faruk; Arslan, Aysenur; Mutlugun, Evren; Erdem, Talha
Fabrication of optoelectronic devices relies on expensive, energy-consuming conventional tools including chemical vapor deposition, lithography, and metal evaporation. Furthermore, the films used in these devices are usually deposited at elevated temperatures (>300 ° C) and under high vacuum, which necessitate further restrictions on the device fabrication. Developing an alternative technology would contribute to the efforts on achieving a sustainable optoelectronics technology. Keeping this in our focus, here we present a simple technique to fabricate visible photodetectors (PDs). These fully solution-processed and transparent metal-semiconductor-metal (MSM) PDs employ silver nanowires (Ag NW) as the transparent electrodes replacing the indium-tin-oxide (ITO) commonly used in optoelectronic devices. By repeatedly spin coating Ag NWs on a glass substrate followed by the coating of zinc oxide nanoparticles, we obtained a highly conductive transparent electrode reaching a sheet resistance of 95 Ω / □ as measured by the four-probe method. Optical spectroscopy revealed that the transmittance of the Ag NW-ZnO films was 84% at 450 nm while the transmittance of the ITO films was 90% at the same wavelength. Following the formation of the conductive film, we scratched it using a heated surgical blade to open a gap. The scanning electron microscope images indicate that a gap of ∼30 μm is opened forming an insulating line. As the active layer, we drop-casted red-emitting CdSe/ZnS core-shell quantum dots (QDs) onto this gap to form a MSM PD. These visible QD-based PDs exhibited responsivities and detectivities up to 8.5 mA / W and 0.95 × 109 Jones, respectively at a bias voltage of 5 V and wavelength of 650 nm. These proof-of-concept PDs show that the environmentally friendly, low-cost, and energy-saving technique presented here can be an alternative to conventional, high-cost, and energy-hungry techniques while fabricating photoconductive devices.