AlGaN quantum well structures for deep-UV LEDs grown by plasma-assisted MBE using sub-monolayer digital-alloying technique

Plasma‐assisted molecular beam epitaxy of AlGaN heterostructures for deep‐ultraviolet optically pumped lasers

“…MQW and single QW (SQW) structures with a nominal thickness of Al x Ga 1 − x N ( x = 0.3–0.5) QWs equal to 2.5–3 nm were fabricated by the SDA technique in which the decrease of the average Al content in QWs relative to that in the barrier layers Al y Ga 1 − y N (| y − x | = 0.1–0.15) was achieved by a few periodic submonolayer GaN insertions, as illustrated in Fig. 2 33, 39.…”

Role of strain in growth kinetics of AlGaN layers during plasma-assisted molecular beam epitaxy

“…AlGaN alloys are of great importance for further progress in the solid-state deep UV optoelectronics with a minimum wavelength of 210 nm [1][2][3][4]. Among different technologies developed for the growth of AlGaN-based heterostructures, the plasma-assisted molecular beam epitaxy (PA MBE) provides unique opportunities that relate to the growth of the heterostructures with a sub-monolayer thickness resolution at relatively low substrate temperatures T S o800 1C, which suppress the surface segregation and improve the sharpness of interfaces.…”

Low-threshold 303 nm lasing in AlGaN-based multiple-quantum well structures with an asymmetric waveguide grown by plasma-assisted molecular beam epitaxy on c-sapphire

“…However, such an alternative technology as molecular beam epitaxy ͑MBE͒ has also succeeded in growing UV-LEDs with the minimum wavelength of 250 nm, 11 as well as MQW structures with high photoluminescence ͑PL͒ efficiency within the spectral range of 220-320 nm. 12,13 Moreover, both NH 3 -based and plasma-assisted ͑PA͒ MBE have been employed to manufacture 410 nm InGaN-based MQW LDs and LEDs on different GaN substrates. 14, 15 We have recently reported the optically pumped lasing at 300.4 nm in an AlGaN MQW structure grown by PA MBE on c-sapphire.…”

“…Three 3-nm-thick QWs with an average x = 0.39, separated by 7-nm-thick barriers layers, were grown by using a submonolayer digital alloying ͑SMDA͒ technique described elsewhere. 13 The composition and thickness parameters of the QW and barrier layers were chosen similar to our previous non-optimized MQW structure 16 to provide the QW emission wavelength at around 300 nm. Other parameters including asymmetric position of the MQW region in the waveguide as well as the composition and thickness of cladding layers have been optimized to place the maximum of a near-field distribution of the fundamental TE mode of electromagnetic field at the MQW active region, as shown in Fig.…”