A5017228256- Conducting polymers and applications
- Organic Electronics and Photovoltaics
- Analytical Chemistry and Sensors
- Gas Sensing Nanomaterials and Sensors
- Nanowire Synthesis and Applications
- Sensor Technology and Measurement Systems
- GaN-based semiconductor devices and materials
- Semiconductor Quantum Structures and Devices
- Spectroscopy Techniques in Biomedical and Chemical Research
- Perovskite Materials and Applications
- Advanced Chemical Sensor Technologies
- Luminescence and Fluorescent Materials
- Thin-Film Transistor Technologies
- Advanced Fluorescence Microscopy Techniques
University of California, San Diego
2016-2019
Abstract While only few organic photodiodes have photoresponse past 1 µm, novel shortwave infrared (SWIR) polymers are emerging, and a better understanding of the limiting factors in narrow bandgap devices is critically needed to predict advance performance. Based on state‐of‐the‐art SWIR bulk heterojunction photodiodes, this work demonstrates model that accounts for increasing electric‐field dependence photocurrent materials. This physical offers an expedient method pinpoint origins...
Abstract This work examines an additive approach that increases dielectric screening to overcome performance challenges in organic shortwave infrared (SWIR) photodiodes. The role of the high‐permittivity additive, camphoric anhydride, exciton dissociation and charge collection processes is revealed through measurements transient photoconductivity electrochemical impedance. Dielectric reduces binding energy increase efficiency lowers trap‐assisted recombination loss, absence any morphological...
NIR-SWIR photoresponsive donor–acceptor polymers enable the detection of infrared light when incorporated into bulk heterojunction photodiodes.
Bulk heterojunction photodiodes are fabricated using a new donor-acceptor polymer with near-infrared absorption edge at 1.2 μm, achieving detectivity up to 1012 Jones wavelength of 1 μm and an excellent linear dynamic range 86 dB. The photodiode is maximized by operating zero bias suppress dark current, while thin 175 nm active layer used facilitate charge collection without reverse bias. Analysis the temperature dependence current spectral response demonstrates 2.8-fold increase in as was...
This work studies organic bulk heterojunction photodiodes with a wide spectral range capable of imaging out to 1.3 μm in the shortwave infrared. Adjustment donor-to-acceptor (polymer:fullerene) ratio shows how blend composition affects density states (DOS) which connects materials and optoelectronic properties provides insight into features relevant understanding dispersive transport recombination narrow bandgap devices. Capacitance spectroscopy transient photocurrent measurements indicate...
We report structural studies on the epitaxial growth of GaAs/GaNAs core-shell nanowires (NWs) patterned Si (111) substrates by self-catalyzed selective area using Gas-Source Molecular Beam Epitaxy. Epitaxial conditions were obtained a combination dry and time-sensitive wet etching SiO2 mask native layer, respectively. found that higher temperatures resulted in yield for GaAs NWs with an optimal temperature 690 °C. The GaNAs shell at 500 °C was to be conformal maintained dislocation-free...
Photosensors responsive to the short wavelength infrared (SWIR) spectra are used in a variety of applications including environmental monitoring, medical diagnosis and optical communications. However, most organic semiconductors do not absorb SWIR region. Here we show novel donor-acceptor polymers with narrow bandgap region, processed into photodiodes structure ITO/PEDOT:PSS/Bulk Heterojunction (BHJ)/Al. The performance devices different polymer structures compared through metrics...
Short wavelength infrared (SWIR) sensors are important to applications in environmental monitoring, medical diagnosis and optical communications, but there only a few organic semiconductors that show optoelectronic response the SWIR region. Recently we demonstrated family of novel donor-acceptor polymers with narrow bandgap responsive region, bulk heterojunction photodiodes based on these detectivity up 1E11 Jones at 1.37 micron, absorption edge extending out 1.7 micron. A photodiode was...