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Observation and tunability of room temperature photoluminescence of GaAs/GaInAs core-multiple-quantum-well shell nanowire structure grown on Si (100) by molecular beam epitaxy.

Park KW, Park CY, Ravindran S, Jang JS, Jo YR, Kim BJ, Lee YT - Nanoscale Res Lett (2014)

Bottom Line: The GaAs/GaInAs core-MQW shell NW surrounded by AlGaAs also shows an enhanced PL intensity due to the improved carrier confinement owing to the presence of an AlGaAs clad layer.The inclined growth of the GaAs NWs produces a core-MQW shell structure having a different PL peak position than that of planar QWs.The PL emission by MQW shell and the ability to tune the PL peak position by varying the shell width make such core-shell NWs highly attractive for realizing next generation ultrasmall light sources and other optoelectronics devices. 81.07.Gf; 81.15.Hi; 78.55.Cr.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Information and Communications, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 500-712, Republic of Korea.

ABSTRACT

Unlabelled: We report the observation of room temperature photoluminescence (PL) emission from GaAs/GaInAs core-multiple-quantum-well (MQW) shell nanowires (NWs) surrounded by AlGaAs grown by molecular beam epitaxy (MBE) using a self-catalyzed technique. PL spectra of the sample show two PL peaks, originating from the GaAs core NWs and the GaInAs MQW shells. The PL peak from the shell structure red-shifts with increasing well width, and the peak position can be tuned by adjusting the width of the MQW shell. The GaAs/GaInAs core-MQW shell NW surrounded by AlGaAs also shows an enhanced PL intensity due to the improved carrier confinement owing to the presence of an AlGaAs clad layer. The inclined growth of the GaAs NWs produces a core-MQW shell structure having a different PL peak position than that of planar QWs. The PL emission by MQW shell and the ability to tune the PL peak position by varying the shell width make such core-shell NWs highly attractive for realizing next generation ultrasmall light sources and other optoelectronics devices.

Pacs: 81.07.Gf; 81.15.Hi; 78.55.Cr.

No MeSH data available.


Cross-sectional schematic of the NW to be grown, band diagram, and the inclined NW growth. (a) Cross-sectional schematic of the NW to be grown. The center region represents the core made of GaAs surrounded by GaInAs shell with AlGaAs layer as the outermost clad layer, (b) band diagram of the NW along the dotted line of Figure 2a, and (c) schematic showing the inclined NW growth.
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Figure 2: Cross-sectional schematic of the NW to be grown, band diagram, and the inclined NW growth. (a) Cross-sectional schematic of the NW to be grown. The center region represents the core made of GaAs surrounded by GaInAs shell with AlGaAs layer as the outermost clad layer, (b) band diagram of the NW along the dotted line of Figure 2a, and (c) schematic showing the inclined NW growth.

Mentions: After completing the growth of GaAs NW core, the MBE chamber pressure and growth temperature were immediately changed to grow GaInAs MQWs. As stated before, the previously grown GaAs NWs are used as the base to grow the GaInAs MQW shell structure. The schematic of the desired core-shell structure is depicted in Figure 2. The MQW shell structure to be grown consists of two Ga0.84In0.16As quantum wells sandwiched between three GaAs barriers surrounded by an Al0.30Ga0.70As cladding layer. The conditions for growing the shell structure were the same as that for growing conventional planar GaInAs MQWs. The growth temperature and MBE background chamber pressure were kept at 570°C and 1.2 × 10-6 mbar, respectively, during growth. The growth temperature was carefully chosen to ensure the incorporation of desired In composition while maintaining high quality of the compositing layers [20]. The V/III ratio was kept around 12 to prevent any axial growth [16]. The GaInAs MQW shell width were 8, 11, and 16 nm, respectively, based on planar growth mode. The barrier between the individual wells was thick enough to avoid any coupling between the QWs. Planar MQWs having a thickness of 8 nm with the same structure and compositions were also grown on (100) GaAs substrate in order to compare the results obtained from the shell structure.


Observation and tunability of room temperature photoluminescence of GaAs/GaInAs core-multiple-quantum-well shell nanowire structure grown on Si (100) by molecular beam epitaxy.

Park KW, Park CY, Ravindran S, Jang JS, Jo YR, Kim BJ, Lee YT - Nanoscale Res Lett (2014)

Cross-sectional schematic of the NW to be grown, band diagram, and the inclined NW growth. (a) Cross-sectional schematic of the NW to be grown. The center region represents the core made of GaAs surrounded by GaInAs shell with AlGaAs layer as the outermost clad layer, (b) band diagram of the NW along the dotted line of Figure 2a, and (c) schematic showing the inclined NW growth.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4257527&req=5

Figure 2: Cross-sectional schematic of the NW to be grown, band diagram, and the inclined NW growth. (a) Cross-sectional schematic of the NW to be grown. The center region represents the core made of GaAs surrounded by GaInAs shell with AlGaAs layer as the outermost clad layer, (b) band diagram of the NW along the dotted line of Figure 2a, and (c) schematic showing the inclined NW growth.
Mentions: After completing the growth of GaAs NW core, the MBE chamber pressure and growth temperature were immediately changed to grow GaInAs MQWs. As stated before, the previously grown GaAs NWs are used as the base to grow the GaInAs MQW shell structure. The schematic of the desired core-shell structure is depicted in Figure 2. The MQW shell structure to be grown consists of two Ga0.84In0.16As quantum wells sandwiched between three GaAs barriers surrounded by an Al0.30Ga0.70As cladding layer. The conditions for growing the shell structure were the same as that for growing conventional planar GaInAs MQWs. The growth temperature and MBE background chamber pressure were kept at 570°C and 1.2 × 10-6 mbar, respectively, during growth. The growth temperature was carefully chosen to ensure the incorporation of desired In composition while maintaining high quality of the compositing layers [20]. The V/III ratio was kept around 12 to prevent any axial growth [16]. The GaInAs MQW shell width were 8, 11, and 16 nm, respectively, based on planar growth mode. The barrier between the individual wells was thick enough to avoid any coupling between the QWs. Planar MQWs having a thickness of 8 nm with the same structure and compositions were also grown on (100) GaAs substrate in order to compare the results obtained from the shell structure.

Bottom Line: The GaAs/GaInAs core-MQW shell NW surrounded by AlGaAs also shows an enhanced PL intensity due to the improved carrier confinement owing to the presence of an AlGaAs clad layer.The inclined growth of the GaAs NWs produces a core-MQW shell structure having a different PL peak position than that of planar QWs.The PL emission by MQW shell and the ability to tune the PL peak position by varying the shell width make such core-shell NWs highly attractive for realizing next generation ultrasmall light sources and other optoelectronics devices. 81.07.Gf; 81.15.Hi; 78.55.Cr.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Information and Communications, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 500-712, Republic of Korea.

ABSTRACT

Unlabelled: We report the observation of room temperature photoluminescence (PL) emission from GaAs/GaInAs core-multiple-quantum-well (MQW) shell nanowires (NWs) surrounded by AlGaAs grown by molecular beam epitaxy (MBE) using a self-catalyzed technique. PL spectra of the sample show two PL peaks, originating from the GaAs core NWs and the GaInAs MQW shells. The PL peak from the shell structure red-shifts with increasing well width, and the peak position can be tuned by adjusting the width of the MQW shell. The GaAs/GaInAs core-MQW shell NW surrounded by AlGaAs also shows an enhanced PL intensity due to the improved carrier confinement owing to the presence of an AlGaAs clad layer. The inclined growth of the GaAs NWs produces a core-MQW shell structure having a different PL peak position than that of planar QWs. The PL emission by MQW shell and the ability to tune the PL peak position by varying the shell width make such core-shell NWs highly attractive for realizing next generation ultrasmall light sources and other optoelectronics devices.

Pacs: 81.07.Gf; 81.15.Hi; 78.55.Cr.

No MeSH data available.