Electrical properties of Si-doped GaAs layers grown on (411)A GaAs substrates by molecular beam epitaxy

Abstract

Electrical properties of Si-doped GaAs layers grown on (411)A GaAs substrates by molecular beam epitaxy (MBE) were investigated for applications to GaAs/AlGaAs resonant tunnelling diodes with atomically flat (411)A GaAs/AlGaAs interfaces over an entire device area. These flat interfaces can be realized by MBE under certain growth conditions (growth temperature T s = 580 • C and V/III pressure ratio of less than or equal to 11). When the V/III pressure ratio is high (above 15) for T s = 580 • C, Si-doped GaAs on a (411)A substrate showed an n-type conduction similar to conventional Si-doped GaAs on (100) substrates. (411)A GaAs/AlGaAs interfaces grown under this condition, however, cannot become as flat and as superior as conventional (100) GaAs/AlGaAs interfaces. On the other hand, when the V/III pressure ratio is 7, an Si-doped GaAs layer on (411)A showed p-type conduction. In the case of a V/III pressure ratio of 10.5 and T s = 580 • C, Si-doped GaAs still showed n-type conduction with the compensation ratio γ (≡ (N D + N A )/(N D − N A )) = 2.3. This result suggests that Si can be used as an n-type dopant in GaAs for GaAs/AlGaAs resonant tunnelling diodes grown on (411)A GaAs substrates with atomically flat (411)A GaAs/AlGaAs interfaces.

Increase in Electrical Conductivity of MOF to Billion-Fold upon Filling the Nanochannels with Conducting Polymer

“…As such, there is not much literature of the Hall-effect measurements on MOF-based materials available apart from the recent reports , of a p-type Co-NDC insulator MOF turned into an n-type semiconductor material upon doping with I 2 ; although the η value was only ∼5 × 10 11 cm –3 . Thus, our results on the Hall-effect measurements are matching well with those of classical inorganic-based semiconductors like doped GaAs as well as those of high-conducting PPy-based systems . The difference in the conductivity value of 1⊃PPy from the four-probe to the Hall-effect measurements could be related to the probe-contact issue.…”

Relationship between silicon incorporation and electrical characteristics for lateral p - n junctions grown on patterned (110) and (100) GaAs substrates

“…It has been reported on the (110) and (N 11)A (N ≤ 4) surfaces that p-type material can be grown under low As 4 :Ga flux ratios, probably because of large-scale Si As formation resulting from the large numbers of As vacancies created during growth [8]. Our studies mirror the published material on both surfaces [8][9][10][11][18][19][20][21][22][23]. If grown under conditions of high As 4 :Ga ratios and/or substrate temperature these surfaces are doped n type, with several factors affecting the conductivity change.…”

“…Surfaces possessing single dangling bond As sites could be doped p type under low As 4 :Ga ratios. This behaviour has been seen on the (110) and (N11)A surfaces, where N ≤ 4 [8][9][10][11]. The (100) surface was always net n type when doped with silicon, as it features a double dangling bond As site [9].…”

“…A large number of papers describing the incorporation of silicon on different surfaces of GaAs have been published, of which [8][9][10][11] are only a representative sample. This work seeks to explain the similarities seen in the electrical characteristics of lateral junctions grown on different substrates, in terms of the accepted view of silicon incorporation in GaAs.…”

Conductive Metal‐Organic Frameworks: Electronic Structure and Electrochemical Applications

“…The electrical conductivity of PPy@MOF was reported to be ∼10 −3 S/cm from its pristine ∼10 −12 S/cm value, attributed to a synergistic effect between conducting chain with host moiety rendering facile charge transport. Moreover, Hall‐effect measurement featured n‐type semiconductor with high‐carrier density (η) of ∼1.5×10 17 cm −3 , resembling classical inorganic‐based semiconductors [194] . Variable temperature conductivity measurement suggested the Mott‐VRH type conduction mechanism.…”