Investigation of 1/f Noise of p-type CdTe Detectors

Abstract

This paper presents the results ofexperimental studies oftransport and noise characteristics of CdTe single crystals. Though no universal mechanism has been identifiedforflicker noise or If noise, it is the most ubiquitous form of noise in nature. Phenomena that have no obvious connection like heartbeat, cell membrane potential, financial data, DNA sequences and transistors exhibit fluctuations with a 1/fcharacter. As the term "If" suggests, a spectral density that increases without limit as frequency decreases, characterizes this kind ofnoise. Flicker noise in the CdTe single crystals was studied. Two CdTe detectors were used; both have p-type conductivity. One of them has lowohmic contacts (F33B8), another one have high-ohmic contact (452D).

Noise characteristics of cold emission cathodes

“…This method is sometimes called as a "drop-off" method [1,2], according to the bottom part of the etched wire which drops down during the final phase of tip etching (see the setup on fig. 1a).…”

“…Cold emission cathode poses point electron source with tip-diameter from 100 to 102 nm, which emits electrons to a relatively wide aperture radius (10-1 rad) with high current density (108 Am-2 and higher) [1]. Cold emission cathodes operate at room temperatures.…”

“…The G-R noise originates from emission processes and individual capture of charge carriers which comes to and from the conduction or valence band in a semiconductor [2]. Mathematically, the G-R noise could be described by equation (1) where the N is the average number of carriers, I is the average (DC) current through the device, and τ is time constant characteristic of the generation-recombination process. We can conclude that the level of G-R noise is proportional to the square of the average (DC) current through the device.…”