The
p-i-n junction structure has garnered great interest from researchers
due to its increased photoactive area and wider space charger region
compared with that of the p-n junction. Herein the ultrawide bandgap
(∼6.7 eV) semiconductor alumina (Al2O3) has been introduced to construct a p-i-n junction with ZnO and
NiO. ZnO–Al2O3–NiO powders are
suitable for electrolyte membrane material of low-temperature solid
oxide fuel cells (LT-SOFCs). The insulating Al2O3 brings a doubled depletion region and more effective charge separation
compared with the p-n junction consisting of ZnO and NiO. The fuel
cell based on the p-i-n junction membrane material delivers an enhanced
maximum power density (MPD) of 917 mW cm–2 along
with a high open-circuit voltage (OCV) of 1.013 V at 550 °C.
An analysis based on the space charge region and energy band alignment
in the p-i-n junction is proposed to account for the appreciable cell
performance and ionic conductivity, as well as the electron blocking
and charge separation ability. This study presents a practical p-i-n
junction design based on ZnO–Al2O3–NiO
via a solution process for LT-SOFC electrolyte material and sheds
light on the extensive exploration of p-i-n junctions applied in LT-SOFCs.
Low
temperature performance and durability have been the main indicators
of fuel cells. In this work, we develop a novel solid oxide fuel cell
(SOFC) by constructing a heterostructure electrolyte based on Gd0.15Ni0.05Ce0.8O2−δ (GNDC) and SnO2, which acquires an open circuit voltage
of 1.026 V and a maximum power density (MPD) of 879.4 mW cm–2 at 550 °C. It is demonstrated that the composites are a hybrid
ionic and protonic conductor with competent conductivity of 0.124–0.220
S cm–1 at 450–550 °C. Further characterization
authenticates the valence state alteration of Ni, creating more oxygen
vacancies during the tests. Also, the existence of the Schottky junction
is detected to confirm the electron suppressing effects due to the
Schottky barrier. These two key points guarantee the superionic conductivity
and promising durability of the cells. This work thus presents a creative
insight for constructing low temperature solid oxide fuel cells (LT-SOFCs).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.