Is CdTe n type or p type?

Is CdTe n type or p type?

They state that undoped CdTe is p-type semiconductor, but addition of In creates n-type material. They define a narrow concentration range over which the CZT transforms from p-type to n-type.

How does CZT work?

The CZT detector works as a semiconductor with direct conversion of gamma radiation to electric signal. This mechanism results in better spatial resolution and sensitivity, what means lower administered dose of radiopharmaceutics and/or shorter acquisition time.

What is a CZT detector?

CZT is a unique semiconductor compared with silicon and germanium detectors – cadmium zinc telluride CZT operates at room temperature and can process >2million photons / second /mm2. Additionally, CZT’s spectroscopic resolution clearly outperforms any commercially available scintillator.

Is semiconductor detector a radiation detector?

A semiconductor detector is a radiation detector which is based on a semiconductor, such as silicon or germanium to measure the effect of incident charged particles or photons.

How do germanium detectors work?

Germanium detectors have a p-i-n structure in which the intrinsic (i) region is sensitive to ionizing radiation, particularly X rays and gamma rays. Under reverse bias, an electric field extends across the intrinsic or depleted region.

Is cadmium telluride toxic?

Cadmium Telluride is a cadmium-tellurium compound. This crystalline compound is mainly used as a solar-cell material and an infrared optical window. It is highly suitable for solar energy conversion. Cadmium Telluride is highly toxic as it contains cadmium.

Is cadmium telluride a semiconductor?

Cadmium telluride (CdTe) (Bonnet (2012))is a direct-bandgap semiconductor with that bandgap well matched to the solar spectrum. CdTe thin-film laboratory cell efficiency of 18.3% has been achieved, and the record module efficiency currently stands at 15.3%.

What does CZT stand for?

CZT

What is a CZT camera?

CZT, short for Cadmium Zinc Telluride, is a compound semiconductor material used in the camera’s detector and represents a breakthrough in many aspects of performance over the Sodium Iodide (NaI) scintillator crystals used in the Anger camera.

What are germanium detectors from?

Germanium detectors are semiconductor diodes having a p-i-n structure in which the intrinsic (i) region is sensitive to ionizing radiation, particularly x rays and gamma rays. Under reverse bias, an electric field extends across the intrinsic or depleted region.

Is cadmium telluride rare?

Only a small amount, estimated to be about 800 metric tons per year, is available. According to USGS, global production in 2007 was 135 metric tons. One gigawatt (GW) of CdTe PV modules would require about 93 metric tons (at current efficiencies and thicknesses).

Why is cadmium telluride used in solar panels?

The benefits of CdTe thin-film solar cells include: High absorption: Cadmium telluride is a direct-bandgap material with bandgap energy that can be tuned from 1.4 to 1.5 (eV), which is nearly optimal for converting sunlight into electricity using a single junction.

What does cadmium telluride do?

High absorption: Cadmium telluride is a direct-bandgap material with bandgap energy that can be tuned from 1.4 to 1.5 (eV), which is nearly optimal for converting sunlight into electricity using a single junction.

Is CdTe toxic?

CdTe is still a potentially toxic material. But the way it is encapsulated in glass in First Solar panels, Sinha said, sharply limits the possibility of inhalation or ingestion exposure. “The semiconductor material is bonded to a sheet of glass under very high temperature,” Sinha explained.

What is spect used for?

The most common uses of SPECT are to help diagnose or monitor brain disorders, heart problems and bone disorders.

What is a radiation detector called?

Detecting radiation is achieved through the use of a variety of instruments. The most common type of radiation detector is a Geiger-Mueller (GM) tube, also called a Geiger counter.

What is cadmium telluride (CdTe)?

Cadmium telluride (CdTe) is a stable crystalline compound formed from cadmium and tellurium. It is mainly used as the semiconducting material in cadmium telluride photovoltaics and an infrared optical window. It is usually sandwiched with cadmium sulfide to form a p–n junction solar PV cell. Typically, CdTe PV cells use a n-i-p structure.

What is the market for cadmium telluride solar cells?

The CdTe solar cell market is dominated by First Solar. In 2011, around 2 GW p of CdTe solar cells were produced; For more details and discussion see cadmium telluride photovoltaics. CdTe can be alloyed with mercury to make a versatile infrared detector material (HgCdTe).

What is the vapor pressure of cadmium telluride?

CdTe has a vapor pressure of zero at ambient temperatures. CdTe is more stable than its parent compounds cadmium and tellurium and most other Cd compounds, due to its high melting point and insolubility. Cadmium telluride is commercially available as a powder, or as crystals.

What are the material properties of cadmium zinc telluride?

We have reviewed the material properties of cadmium zinc telluride with Zn content in the range of 10–20%. The yield of material suitable for this application remains relatively low, and this continues to limit to some extent the applications of this technology due to the associated high material costs.