Université de Neuchâtel

Latest developments in GaN-based quantum devices for infrared optoelectronics

Monroy, Eva ; Guillot, Fabien ; Leconte, Sylvain ; Nevou, Laurent ; Doyennette, Laeticia ; Tchernycheva, Maria ; Julien, François H. ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Hofstetter, Daniel

In: Journal of Materials Science : Materials in Electronics, 2008, vol. 19, no. 8-9, p. 821-827

In this work, we summarize the latest progress in intersubband devices based on GaN/AlN nanostructures for operation in the near-infrared. We first discuss the growth and characterization of ultra-thin GaN/AlN quantum well and quantum dot superlattices by plasma-assisted molecular-beam epitaxy. Then, we present the performance of nitride-based infrared photodetectors and electro-optical...

Université de Neuchâtel

Intersubband Transition-Based Processes and Devices in AlN/GaN-Based Heterostructures

Hofstetter, Daniel ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Théron, Ricardo ; Wu, Hong ; Schaff, William J. ; Dawlaty, Jahan ; George, Paul A. ; Eastman, Lester F. ; Rana, Farhan ; Kandaswamy, Prem K. ; Guillot, Fabien ; Monroy, Eva

In: Proceedings of the IEEE, 2010, vol. 98, no. 7, p. 1234-1248

We report on the physics, epitaxial growth, fabrication, and characterization of optoelectronic devices based on intersubband transitions in the AlN/GaN material system. While in 1999, only results of optical absorption experiments could be shown, photodetectors and modulators with operation frequencies beyond 10 GHz as well as optically pumped light emitters have been demonstrated recently. This...

Université de Neuchâtel

High frequency measurements on an AlN/GaN-based intersubband detector at 1550 and 780 nm

Hofstetter, Daniel ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Dawlaty, Jahan ; George, Paul A. ; Rana, Farhan ; Guillot, Fabien ; Monroy, Eva

In: Journal of Applied Physics, 2008, vol. 92, p. 231104 1-3

We report on high frequency measurements on an AlN/GaN-based intersubband detector using mode-locked solid state lasers. Our experiments involving laser wavelengths of 1550 and 780 nm demonstrate not only the capability of such devices to work both at the fundamental and at a higher order intersubband transition, but they also allowed us to push the high frequency detection limit up to a value...

Université de Neuchâtel

GaN/AlN short-period superlattices for intersubband optoelectronics: A systematic study of their epitaxial growth, design, and performance

Kandaswamy, Prem K. ; Guillot, Fabien ; Bellet-Amalric, Edith ; Monroy, Eva ; Nevou, Laurent ; Tchernycheva, Maria ; Michon, A. ; Julien, François H. ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Hofstetter, Daniel ; Remmele, T. ; Albrecht, M. ; Birner, S. ; Dang, Le Si

In: Journal of Applied Physics, 2008, vol. 104, no. 9, p. 093501 1-8

We have studied the effect of growth and design parameters on the performance of Si-doped GaN/AlN multiquantum-well (MQW) structures for intersubband optoelectronics in the near infrared. The samples under study display infrared absorption in the 1.3–1.9 μm wavelength range, originating from the photoexcitation of electrons from the first to the second electronic level in the QWs. A...

Université de Neuchâtel

Monolithically integrated UV/IR-photodetectors based on an AlN/GaN-based superlattice grown on an AlGaN buffer layer

Hofstetter, Daniel ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Théron, Ricardo ; Guillot, Fabien ; Monroy, Eva ; Golka, Sebastian ; Strasser, Gottfried

In: Physica status solidi (c), 2009, vol. 6, no. 2, p. S818-821

In this article, we demonstrate closely spaced, monolithically integrated photodetectors in two largely different wavelength ranges. The epitaxial structure of the devices was grown by plasma-assisted molecular-beam epitaxy on an AlN-on-sapphire template; it consists of a Si-doped AlGaN thin film, and a nearly strain compensated 40 period AlN/GaN superlattice with 1.0 nm thick GaN quantum wells...

Université de Neuchâtel

MBE growth of AlN/GaN-based photovoltaic intersubband photodetectors

Monroy, Eva ; Guillot, Fabien ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Hofstetter, Daniel

In: Physica status solidi (a), 2008, vol. 205, no. 5, p. 1060-1063

We report on the molecular-beam epitaxial growth, fabrication and characterization of AlN/GaN photovoltaic quantum well infrared photodetectors operating at 1.55 µm. Devices display a spectrally-narrow photovoltaic response to p-polarized light in the near infrared at room temperature. We have analysed the effect of the growth temperature, quantum well thickness, and number of periods in the...

Université de Neuchâtel

Monolithically integrated AlGaN/GaN/AlN-based solar-blind ultraviolet and near-infrared detectors

Hofstetter, Daniel ; Théron, Ricardo ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Golka, Sebastian ; Strasser, Gottfried ; Guillot, Fabien ; Monroy, Eva

In: Electronics Letters, 2008, vol. 44, no. 16, p. 986-987

Closely spaced, monolithically integrated photodetectors in two largely different wavelengths ranges are demonstrated. The device structure was grown by plasma-assisted molecular-beam epitaxy on an AlN-on-sapphire template, and it consists of a Si-doped AlGaN thin film, and a nearly strain compensated 40 period AlN/GaN superlattice with 1.0 nm-thick GaN quantum wells and 2.0 nm-thick AlN...

Université de Neuchâtel

High frequency (f=2.37 GHz) room temperature operation of 1.55 µm AlN/GaN-based intersubband detector

Giorgetta, Fabrizio R. ; Baumann, Esther ; Guillot, Fabien ; Monroy, Eva ; Hofstetter, Daniel

In: Electronics Letters, 2007, vol. 43, no. 3, p. 185-187

The fabrication and high frequency operation of a room temperature 1.55 µm intersubband detector based on a regular AlN/GaN superlattice is reported. This photovoltaic device was capable of detecting a sinusoidally modulated laser beam at high frequencies of up to 2.37 GHz.

Université de Neuchâtel

MBE growth of nitride-based photovoltaic intersubband detectors

Monroy, Eva ; Guillot, Fabien ; Leconte, Sylvain ; Bellet-Amalric, Edith ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Hofstetter, Daniel ; Nevou, Laurent ; Tchernycheva, Maria ; Doyennette, Laeticia ; Julien, François H. ; Remmele, T. ; Albrecht, M.

In: Superlattices and Microstructures, 2006, vol. 40, no. 4-6, p. 418-425

In this work, we present the plasma-assisted molecular-beam epitaxial growth of quantum well infrared photodetector (QWIP) structures, including the Si-doped GaN/AlN short-period superlattice of the active region, conductive AlGaN claddings and integration of the final device. The growth of Si-doped GaN/AlN multiple quantum well (QW) structures is optimized by controlling substrate temperature,...

Université de Neuchâtel

GaN/AlN electro-optical modulator prototype at telecommunication wavelengths

Baumann, Esther ; Giorgetta, Fabrizio R. ; Hofstetter, Daniel ; Guillot, Fabien ; Leconte, Sylvain ; Bellet-Amalric, Edith ; Monroy, Eva

In: Physica status solidi (c), 2007, vol. 4, no. 5, p. 1621-1624

We report on a prototype electro-optical modulator at telecommunication wavelength based on intersubband (ISB) transitions in a short-period GaN/AlN superlattice (SL). The device has a vertical architecture resembling a nitride-based high-electron mobility transistor, whose barrier layer has been replaced by a 5 period SL. By applying an electrical field, we were able to influence the...