Acceptor Luminescence in High-Purityn-Type GaAs

GaAs Luminescence Transitions to Acceptors in Magnetic Fields

“…3). Rossi et al [5] have measured this behaviour of the 1.493 eV line up to 4.5 T. They explain the smaller slope by a band filling effect, which a t low fields produces a smaller shift than expected from the magnetic field dependence of the band edge. At higher fields, since the density of states in the lowest Landau level increases linearly in the magnetic field, this effect should vanish and the shift should approach that of the lowest Landau level.…”

“…I n high-purity samples, the broad 1.490 eV line is resolved into several lines [5], which have been identified as (DO, AO) and electron to neutral acceptor (e, AO) transitions from their behaviour in magnetic fields up to 4.5 T. The shifts of the peak energy of the (DO, Ao) lines as a function of the magnetic field have been qualitatively interpreted in terms of the variation of the donor binding energy and of the Coulomb term [5].…”

Tuning of the electron effective mass and exciton wavefunction size in GaAs1−xNx

“…2 the C-related level stays ÿxed in energy, as reported in Ref. [11], while the conduction band bottom and the valence band top shift upon application of B. Therefore, the shift of the (e; C) band can be ascribed to the mere shift of the conduction band bottom.…”

“…Continuous lines in Fig. 3(a) are a ÿt of E d = (˝e=2m * e )B, to the (e; C) shift in the B-linear region of E d [11]. This method provides a direct measurement of m * e and it has been applied successfully to all samples considered.…”

Novel Conductive and Transparent Optical Fiber Probe for Multifunctional Scanning Tunneling Microscopy

“…At both temperatures, the STML becomes observable when the applied sample bias exceeds −1.5 V in the negative bias region, and saturates around a sample bias of −5.0 to −6.0 V. The direct band gaps of GaAs at RT and 80 K can be calculated empirically as 1.424 and 1.507 eV, respectively [Evoy et al,1999;Alvarado et al, 1991;Rossi et al, 1970], which are in good agreement with the above observed threshold 'turn on' voltage (−1.5 V) shown in figures 14(a) and (b). In the positive bias region, a weak photon emission can be observed when the bias exceeds∼+3.5 V. At RT the maximum value of the STML intensity at negative sample bias is about five times higher than that at positive sample bias, as shown in figure 14(a), while at 80 K the maximum value of STML intensity at negative sample bias is about 15 times higher than that at positive sample bias, as shown in figure 14(b).…”