Kavli Affiliate: Grace Xing
| First 5 Authors: Shivali Agrawal, Len van Deurzen, Jimy Encomendero, Joseph E. Dill, Hsin Wei
| Summary:
Ultrawide bandgap heterojunction p-n diodes with polarization-induced AlGaN
p-type layers are demonstrated using plasma-assisted molecular beam epitaxy on
bulk AlN substrates. Current-voltage characteristics show a turn on voltage of
$V_{text{bi}}approx5.5$ V, a minimum room temperature ideality factor of
$etaapprox 1.63$, and more than 12 orders of current modulation at room
temperature. Stable current operation of the ultrawide bandgap semiconductor
diode is measured up to a temperature of 300$^circ$C. The one-sided n$^{+}$-p
heterojunction diode design enables a direct measurement of the spatial
distribution of polarization-induced mobile hole density in the graded AlGaN
layer from the capacitance-voltage profile. The measured average mobile hole
density is $p sim 5.7 times 10^{17}$ cm$^{-3}$, in close agreement with what
is theoretically expected from distributed polarization doping. Light emission
peaked at 260 nm (4.78 eV) observed in electroluminescence corresponds to
interband radiative recombination in the n$^{+}$ AlGaN layer. A much weaker
deep-level emission band observed at 3.4 eV is attributed to cation-vacancy and
silicon complexes in the heavily Si-doped AlGaN layer. These results
demonstrate that distributed polarization doping enables ultrawide bandgap
semiconductor heterojunction p-n diodes that have wide applications ranging
from power electronics to deep-ultraviolet photonics. These devices can operate
at high temperatures and in harsh environments.
| Search Query: ArXiv Query: search_query=au:”Grace Xing”&id_list=&start=0&max_results=3