We fabricated extended SWIR photodetectors with cutoff wavelength of 2.3 μm by using lattice-matched InGaAs/GaAsSb type-II quantum wells as an absorption layer. The 100-pair InGaAs/GaAsSb quantum wells and InGaAs as a cap layer were grown on an n-type InP substrate by molecular-beam epitaxy. The p-n junction was formed by selective zinc diffusion using rapid thermal annealing. For dark current reduction, photodetector with a barrier layer between the absorbing layer and the cap layer was also fabricated. In each device, in addition to absorption in the InGaAs cap layer, absorption which is possibly originating from the quantum well layer was observed in a wavelength range from 1.6 μm to 2.3 μm. By comparing dark current of each device, dark current reduction by the barrier layer was also confirmed.
We investigated the heteroepitaxial growth of GaSb on Si(001) substrates. High-quality GaSb films were grown on Si substrates by using an AlSb initiation layer. When small AlSb islands were formed on the Si substrate before the GaSb growth, two-dimensional GaSb film was grown. In contrast, without small AlSb islands, large GaSb islands formed on the substrate. Therefore, the AlSb islands played an important role in preventing excessive surface diffusion of Ga atoms on the Si surface and promoting two-dimensional growth of GaSb. A narrow X-ray diffraction rocking curve (around 200 arcsec) was obtained by optimizing the growth temperature and the thickness of the AlSb initiation layer. High-quality GaSb/AlGaSb and InGaSb/AlGaSb MQW samples were also grown on a Si substrate by using this method. At room temperature, these samples gave a strong emission at 1.55 μm, which is a wavelength used by fiber optic communications systems. Furthermore, we could control the emission wavelength by simply changing the well width. The emission energy was in good agreement with the theoretical curve. The temperature dependence of the PL intensity indicated a large activation energy (~77.6 meV) from the GaSb QWs. These results indicate that the fabricated QW structure had high crystalline quality and that GaSb quantum wells can be fabricated on Si for optical devices operating above room temperature.
We present a fabrication technique for creating high-quality structures of antimonide-based quantum dots (Sb-based QDs), which show long-wavelength emissions for fiber-optic communications. By using the Sb-based QDs as the active medium, we successfully demonstrated optical-emissions in the 1.3- and 1.5-μm wavebands from a long-wavelength vertical-cavity surface emitting laser (VCSEL) structure fabricated on a GaAs substrate. Additionally, we describe a growth technique for Sb-based QDs on a silicon wafer, which may become novel-materials for silicon photonics technology.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.