MOCVD Epitaxy & Synthesis Lab
Lehigh University's Smith Laboratory facility supports research in the fields of semiconductor nanostructure, semiconductor optoelectronics, photonics integrated circuits, and III-Nitride and III-V semiconductor devices.
MOCVD Epitaxy for III-V and III-Nitride Semiconductors
VEECO P-75 GaN based MOCVD Reactor
The P-75 reactor provides the capability to research AllnGaN materials and devices for optoelectronics and nanostructures. The reactor is equipped with 6 metalorganic sources (TMIn, TMGa, TEGa, TMAI and Cp2Mg), and is capable of growing compound semiconductor materials containing In, Ga, Al and N. Dopant species of Mg and Si are available for device applications. The P-75 reactor may also be used in research on low-cost and compact deep-UV light sources using AllnGaN semiconductor nanostructures, efficient white-light LEDs, InGaN semiconductor nanostructure optoelectronis, GaN based electronic devices and InN-based semiconductor thin film and nanostructures. A new line for Cr/Mn-precursor has also been installed for using III-Nitride spintronics materials.
The P-75 reactor is equipped with RealTemp (R) in-situ instrumentation, which allows real-time correction of emissivity during epitaxial deposition, in order to yield reliable and repeatable temperature readings. The utilization of RealTemp (R) enables us to determine extremely accurate growth rates, to conduct quantitative analyses of buffer layers and to estimate the composition of ternary and quaternary materials. Due to the high degree of repeatability from one run to the next, the PI's group is able to focus on making small adjustments needed to closely examine the novel compound semiconductor materials and ultimately improve our epi results.
VEECO D-125 GaAs/InP based MOCVD Reactor
The D-125 MOCVD system is dedicated to optoelectronics and nanostructure research on GaAs/InP substrates. The D-125 reactor has been customized for 12 metalorganic sources (2 TMGa, 2 TMIn, 2 TMAI, TMSb, UDMhy, TBP, TBA, DEXn and CBr4), which allows for the versatile growth of novel and new semiconductor material systems. The reactor is capable of growing compound semiconductor materials containing In, Ga, Al, As, P, Sb and N. Elements of Zn, C and Si are also available in this reactor for doping purposes. The D-125 reactor is also used to grow dilute-nitride and SB-based semiconductor nanostructure optoelectronics devices, quantum dots lasers and amplifiers, interdiffused quantum dots, solar cell and terahertz sources. The D-125 is also equipped with an in-situ RealTemp (R) instrument.
Additionally, extensive material characterization facilities are available to support such operations as Hall measurements, optical reflectance, photoluminescence mapping, x-ray diffractometering, atomic force microscopy, confocal and scanning near-field optical microscopy.
Organic Photonics and Photovoltaic LabORATORY
The organic optoelectronics lab is dedicated to the fabrication and investigation of organic materials for photonics applications. A high-vacuum system with a low-temperature evaporator, quartz microbalance, and a temperature-controlled substrate holder is used to study molecular beam deposition of small molecule organic materials. Molecular beam deposition of small organic molecules is used to form dense, single-component supramolecular assemblies as thin films on various substrates. The high density of optimized small molecules allows to achieve record-high third-order nonlinearity in a flexible, highly homogenous amorphous material that possesses large third-order nonlinearities and has been used to demonstrate ultra-high-speed silicon-organic-hybrid all-optical switches on the silicon photonics platform.
In the area of photovoltaic, the effort in the laboratory is to design and synthesize custom-tailored conjugated materials that exploit unconventional molecular and electronic structure, and explore their applications in devices. These materials display unexplored chemical and physical properties that show potential for enhancing the performance of organic solar cells (OSCs) and organic field-effect transistors (OFETs).
Phosphors and Nanomaterials Synthesis
The phosphor synthesis facility is available for use in enabling the synthesis of various red phosphor materials used for white LED devices. This facility includes equipment used in determining the compsition of phosphor. The centrifuge is capable of separating powder from the suspension and the furnace can operate to a high temperature of 1100 degrees C.
The rapid convection deposition facility is available for the use of performing monolayer colloidal deposition of nanosphere and microsphere arrays (100 nm-1 um)** on LEDs and solar cells. The process has been optimized for enabling the deposition of these colloidal particales for monolayer, sub-monolayer and multilayer array arrangements, which are useful in optimizing the light extraction and collection efficiency in LEDs and solar cells.