To study AlGaAs p‐n heterojunctions and optical and transport properties of electrically injected minority carriers (electrons) in p‐Al0.25Ga0.75As, we have tested the performance of Al0.6Ga0.4As/Al0.25Ga0.75 As/Al0.6Ga0.4As NpN double‐heterojunction bipolar transistors (DHBTs). The transistors exhibited a common emitter current gain (β) as high as 400 at a current density of 2 kA cm−2. From the Gummel plots, the ideality factors (n) of emitter‐base and base‐collector junctions were as low as 1.37 and 1.01, respectively, indicating high quality of both the junctions. Assuming a unity current injection efficiency, we obtain an electron diffusion length of 1.2 μm for an acceptor density of 6.0×1018 cm−3 in p‐Al0.25Ga0.75As. Due to the wide band‐gap materials, the device has the potential for useful operation at very high temperatures. The device also works as a bright red light emitter when the emitter‐base junction is forward biased and the collector is either floating or forward biased, indicating dominan...
[1]
H. Beneking,et al.
New technique for determination of static emitter and collector series resistances of bipolar transistors
,
1981
.
[2]
R. Kiehl,et al.
High‐gain, high‐frequency AlGaAs/GaAs graded band‐gap base bipolar transistors with a Be diffusion setback layer in the base
,
1985
.
[3]
Paul R. Berger,et al.
Substantial improvement by substrate misorientation in dc performance of Al0.5Ga0.5As/GaAs/Al0.5Ga0.5As double‐heterojunction NpN bipolar transistors grown by molecular beam epitaxy
,
1991
.
[4]
T. E. Zipperian,et al.
GaP/AlxGa1−xP heterojunction transistors for high‐temperature electronic applications
,
1983
.
[5]
R. Fischer,et al.
Comprehensive analysis of Si-doped Al x Ga 1-x As (x=0 to 1): Theory and experiments
,
1984
.
[6]
E. H. C. Parker,et al.
The Technology and physics of molecular beam epitaxy
,
1985
.