Photoelectrochemical cells are devices that can convert solar radiation to hydrogen gas through a water decomposition
process. In this process, energy is converted from incident photons to the bonds of the generated H2 molecules. The solar
radiation absorption, electron-hole pair splitting, and photoelectrolysis half reactions all occur in the vicinity of the
electrode-electrolyte interface. As a result, engineering the electrode material and its interaction with the electrolyte is
important in investigating and improving the energy conversion process in these devices. III-V nitride materials are
promising candidates for photoelectrochemical energy applications. We demonstrate solar-to-hydrogen conversion in
these cells using p-type GaN and n-type InGaN as a photocathode and photoanode material, respectively. Additionally,
we demonstrate heteroepitaxial MOCVD growth of GaP on Si, enabling future work in developing GaPN as a
photocathode material.
The development of low cost and compact biological agent identification and detection systems, which can
be employed in place-and-forget applications or on unmanned vehicles, is constrained by the photodetector currently
available. The commonly used photomultiplier tube has significant disadvantages that include high cost, fragility,
high voltage operation and poor quantum efficiency in the deep ultraviolet (240-260nm) necessary for methods such
as fluorescence-free Raman spectroscopy. A III-Nitride/ SiC separate absorption and multiplication avalanche
photodiode (SAM-APD) offers a novel approach for fabricating high gain photodetectors with tunable absorption
over a wide spectrum from the visible to deep ultraviolet. However, unlike conventional heterojunction SAM APDs,
the performance of these devices are affected by the presence of defects and polarization induced charge at the
heterointerface arising from the lattice mismatch and difference in spontaneous polarization between the GaN
absorption and the SiC multiplication regions. In this paper we report on the role of defect density and interface
charge on the performance of GaN/SiC SAM APDs through simulations of the electric field profile within this
device structure and experimental results on fabricated APDs. These devices exhibit a low dark current below 0.1
nA before avalanche breakdown and high avalanche gain in excess of 1000 with active areas 25x larger than that of
state of the art GaN APDs. A responsivity of 4 A/W was measured at 365 nm when biased near avalanche
breakdown.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.