Formation of In0.5Ga0.5As ring-and-hole structure by droplet molecular beam epitaxy

Sharp contrast of the density and size of Ga metal droplets on photolithographically patterned GaAs (100) by droplet epitaxy under an identical growth environment

“…This process can be described by the Volmer–Weber growth model 3. Subsequent expose of LPMDs to group V flux results in the crystallization of metal droplets (MDs) into various configurations of semiconductor nano‐crystals through the chemical reaction between group III and V elements 4–7. Homo‐epitaxial nano‐crystalline templates can be fabricated and thus have been used for the fabrication of many hybrid quantum and nano‐structures 6, 7.…”

Holed nanostructures formed by aluminum droplets on a GaAs substrate

“…A significant advantage of droplet epitaxy growth is its flexibility in that it is applicable to both latticemismatched and lattice-matched systems. Since the initial work by Koguchi et al [10], various dot-like [11][12][13], ring-like [14][15][16][17], and hole-like nanostructures [18][19][20] have been observed on Ⅲ-Ⅴ semiconductors.…”

“…The holed nanostructures, first demonstrated by Wang et al [21], are particularly promising candidates for the formation of uniform and low-density quantum rings [22][23][24]. However, all the previously published work has involved the formation of nanostructures from gallium (Ga) or indium (In) droplets [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], and there has been no report of aluminum (Al) droplets on GaAs substrates, although there have been a few of papers involving Al droplets [11,25]. Investigation of the nanostructures formed from Al droplets will not only enrich our knowledge of group Ⅲ droplet epitaxy and facilitate an understanding of provide a solid understanding of such a simple and novel molecular beam epitaxy (MBE) growth process [26].…”

Surface morphology and photoluminescence of InGaAs quantum rings grown by droplet epitaxy with varying In0.5Ga0.5 droplet amount

“…Intensity of the 901-polarized spectrum (minimum) was 30% less than the 01-polarized spectrum (maximum). The polarized light was corresponding to the elongation along [0 1 -1] of the QRs, indicating the non-perfect circularity or anisotropy of the QR structures [8,13,14]. Note that the monochromator gratings that had no polarization effect by the constant emissions from a reference sample with non-polarized (1 0 0) flat layers (not the experimental samples) along different crystal directions were confirmed, as shown in the inset of Fig.…”

“…One merit of QRs is the magnetic properties, which is related to the possibility of inducting persistent currents [6]. Recently, we have studied the effects of substrate temperature during droplet formation on the InGaAs QRs, which mainly focus on the surface morphology characterization [7,8]. Besides, the photoluminescence (PL) characterization is another approach for investigating the properties of the droplet-epitaxy-grown QRs.…”