An application of electrolytic deposition for the electronic passivation of GaAs surfaces through the formation of thin organic films

Enhancement of photoluminescence from near-surface quantum dots by suppression of surface state density

“…[7][8][9] Lunt et al 9 had reported that the deposition of HSCH 2 CH 2 SH and ClC 6 H 4 SH led to an enhancement in the luminescence by a factor of P ¼ 1.5 $ 2. Asai et al 10 also observed a similar luminescence enhancement of GaAs coated with a dioctadecyl-dithiocarbamate film (P $ 2). Nevertheless, it should be noted that all these films were based on multilayers, i.e.…”

“…Nevertheless, it should be noted that all these films were based on multilayers, i.e. a few monolayers 10 or bulk films of more than 1 mm, 7,8 which contain inhomogeneities and defects. Nakagawa et al have reported 11 the deposition of ODT monolayers on bulk GaAs (N d $ 5 Â 10 16 cm À3 ); however, they could not observe any significant increase in photoluminescence.…”

“…To reduce the densities of surface defects (i.e. recombination centers) and to avoid surface degradation, many approaches were reported treating the surfaces with various sulfides and mercaptans, such as Na 2 SÁ9H 2 O, (NH 4 ) 2 S, HSCH 2 CH 2 SH, ClC 6 H 4 SH, etc., [7][8][9][10] and the passivation effects were discussed in terms of enhancement in the photoluminescence. However, these surface coatings consist of a few monolayers 10 or can even be thicker than 1 mm, 7,8 including certain inhomogeneities and defects.…”

“…recombination centers) and to avoid surface degradation, many approaches were reported treating the surfaces with various sulfides and mercaptans, such as Na 2 SÁ9H 2 O, (NH 4 ) 2 S, HSCH 2 CH 2 SH, ClC 6 H 4 SH, etc., [7][8][9][10] and the passivation effects were discussed in terms of enhancement in the photoluminescence. However, these surface coatings consist of a few monolayers 10 or can even be thicker than 1 mm, 7,8 including certain inhomogeneities and defects. To improve the homogeneity of the surface coating, Nakagawa et al 11 have deposited a self-assembled monolayer of ODT on bulk GaAs (N d $ 5 Â 10 16 cm À3 ), but they could not resolve any changes in photoluminescence.…”

Influence of Thiol Coupling on Photoluminescence of Near Surface InAs Quantum Dots

“…However, effects of the surface modification on the luminescence properties have been discussed in terms of increased PL intensity and PL decay time only for bulk GaAs [15,16]. In previous studies, we demonstrated the electrochemical stabilization of the GaAs surface by the ODT monolayer deposition in aqueous electrolytes [2].…”