Msm photodetector thesis

However, the responsivity total signal produced from a from a given optical input is quite low compared to p-i-n photodiodes. Previously published results for Schottky barriers on In0.

Photodetectors are being used in more regions of everyday life from the bar code scanner at the grocery store, to the receiver for your remote control on the VCR, to the photoreceiver at the end of a fiber optic cable in a communication system.

The reduced barrier height for CTO is caused by tunneling through the sputter-damaged cap layer. An MSM photodetector is inherently planar and requires only a single photolithography step which is compatible with existing field effect transistor FET technology. The Schottky barrier height was measured for five different materials on undoped In0.

Since MSM diodes have such simple technology, any improvement in responsivity, the current limiting factor to their widespread use, will allow this class of photodetectors to supplant existing photodetectors in the marketplace. Brief Description of Work and Results: This could be accomplished by investigations to suppress surface recombination through passivation, to minimize surface reflections and therefore collect a greater percentage of the incident light, to improve the carrier lifetime, and to better understand the internal gain mechanisms.

Paul R. Berger

MSM photodetectors are very high speed devices due to their low capacitance, and they typically have very low dark currents current produced without incident light. A new model which takes into account both the forward and reverse biased junctions has been developed from the small signal model of a Schottky diode.

No anti-reflection AR coating was utilized over the bare semiconductor surface.

The barrier heights were measured using I-V measurements. For further information contact: The transparent contact prevents shadowing of the active layer by the electrodes, thus allowing greater collection of incident light.

Metal-semiconductor-metal MSM photodiodes with electrodes fabricated from the transparent conductor cadmium tin oxide CTO have been shown to double photoresponsivity.

Due to the high series resistance created by the undoped In0. This new model was fit to data obtained from S-parameter measurements, and incorporates both the transit time response and RC time constant response. Bandwidth was elevated nearly an order of magnitude over a previous MSM photodiode design with an abrupt heterointerface.

We are investigating ways Msm photodetector thesis improve the responsivity of MSM photodiodes. CTO has greater transmission properties at the wavelengths appropriate for In0. The main causes for the low responsivity is the reflection from the surface metals and semiconductor surface, the finite carrier lifetime as the carriers traverse the gap between the electrodes before being collected, absorption of incident light outside the region in which photogenerated carriers can be collected by the electrodes, and surface recombination currents and deep traps within the semiconductor material which may lower the detected optical signal.

An MSM photodetector consists of interdigitated Schottky metal contacts on top of an active absorption layer. Though MSMs are generally believed to be limited by the transit time of electrons, it is possible the larger resistivity of CTO has become a significant factor, making the MSMs RC time constant limited instead.

Metal-semiconductor-metal MSM photodetectors offer an attractive benefit over alternative photodetectors such as conventional p-i-n photodiodes. Previous models of MSMs only account for one of the two back-to-back Schottky diodes.

A metal-semiconductor-metal MSM In0. The barrier height of CTO on i-In0. Wei Gao graduated with Ph. Metal-semiconductor-metal MSM photodiodes with an In0. The Schottky barrier heights were determined to be 0.

By increasing the responsivity, simple easy to manufacture photodiodes sensitive to low-light levels would be feasible.Investigation of Optical Properties of Zinc Oxide Photodetector A thesis submitted in partial fulfillment of the requirements for the degree of.

The MSM photodetector was chosen as a good candidate for use in our optical interconnect architectures due to the use of standard silicon (Si) substrates, the potential for high speed operation, and the applicability to 2D detector arrays 1 '2. CHARGE COLLECTION MECHANISMS IN A SUB-MICRON GRATED MSM PHOTODETECTOR: FIELD ANALYSIS A Thesis presented to the faculty of the Graduate School.

OPTIMIZATION OF CHARGE COLLECTION EFFICIENCY IN MSM PHOTODETECTOR A Thesis presented to the Faculty of Graduate School University of Missouri-Columbia. High Performance, Low Cost Lateral Metal-Semiconductor-Metal Photodetector for Large Area Indirect X-Ray Imaging by Sina Ghanbarzadeh A thesis presented to the University of Waterloo.

with Integrated Photodetector for Optical Interconnects A Ph. D. Thesis Presented to The Academic Faculty by InGaAs thin-film Inverted-MSM photodetector with a responsivity of A/W at a wavelength of µm was post-integrated onto the circuit.

The circuit has a overall.

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Msm photodetector thesis
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