Luminescence and photoconductivity of undoped p-GaSb

Abstract

A doubly ionizable acceptor (binding energies of EA = 34.5 meV, EC = 102 meV), which is responsible for the hole concentration in undoped GaSb, is identified by photoluminescence experiments at 2 K. Growth experiments, using nonstoichiometric melts, show that this acceptor is connected with a lack of antimony in the crystals. Experimental photoluminescence data, concerning the free exciton recombination at 810 meV and an emission line at 795.5 meV (possibly a bound exciton) as well as new phonon satellites, are presented. Finally, photoconductance measurements at the same samples give further information about excitons in GaSb.

The Surface and Optical Properties of Passivated GaSb with Different Passivating Agents

“…For the untreated sample, two broad emissions centered at 777 meV and 794 meV can be observed, which is associated with the transition from the conduction band to the native acceptor level V Ga Ga Sb (A) and bound-edge-related transitions (BE 4 ). For the samples passivated by (NH 4 ) 2 S and Na 2 S, except for the two main peaks we can also observe a emission peak at 757 meV which is corresponding to the acceptor transition called B peak, from previously reports which is associated with the complex V Ga Ga Sb V Ga , and other new one located at 749 meV is supposed to be A-LO peak, which as accompanied by an LO photo replica 30 meV below the A level, and 798 meV, 801 meV are corresponding to the BE1 and BE2 [18][19][20]. When the temperature rising, besides A and BE 4 emission, other emission disappeared gradually.…”

Brief Review of Epitaxy and Emission Properties of GaSb and Related Semiconductors

“…The typical surface morphologies of GaSb epilayers that were grown at 550 °C from a 660 °C from an Sb-rich melt are as shown in Figure 2. CVD growth of GaSb has been reported by Jakowetzet et al and MOCVD growth of GaSb has also been performed [16,17]. Typical surface morphologies of GaSb epilayers (a) grown on a (100) substrate at 550 °C from a Ga-rich melt and (b) on a 7° off-axis (111) substrate at 660 °C from an Sb-rich melt.…”

“…The typical surface morphologies of GaSb epilayers that were grown at 550 • C from a 660 • C from an Sb-rich melt are as shown in Figure 2. CVD growth of GaSb has been reported by Jakowetzet et al and MOCVD growth of GaSb has also been performed [16,17]. Liquid phase epitaxy (LPE) was the earliest method used in the extended growth of GaSb-based materials, and there are numerous reports on the growth of GaSb by LPE techniques.…”

“…The luminescence properties of undoped p-GaSb were studied as early as 1972 by Jakowetz et al, who observed that a doubly-ionizable acceptor affected the concentration of holes in undoped GaSb [16]. Figure 6 shows the experimental PL data for undoped GaSb.…”

“…The lines A, B and C were interpreted as transitions from the conduction band to the three acceptor levels. The acceptor ionization energies denoted by EA, EB and EC were 34.5, 55 and 102 meV, respectively [16,[31][32][33]. The energy positions and corresponding interpretations are listed in Table 3.…”