State and distribution of point defects in doped and undoped bridgman-grown CdTe single crystals

Impurity gettering effect of Te inclusions in CdZnTe single crystals

“…During the subsequent CZT cooling, the liquid Te-rich droplet experiences a quasi-symmetrical crystallization from the droplet edge to droplet center. Table 1 gives the segregation coefficient (k) of different impurities in CZT [7][8][9][10]. It is easy to see the k value of Na, In, Ag and Bi are very low, which means the segregation of these impurities is very serious and will result in exclusion of these four impurities into the Te-rich droplet embedded in the surrounding solid CZT matrix.…”

Non‐stoichiometry related defects at the melt growth of semiconductor compound crystals – a review

“…Benz [2] we showed that under uncontrolled growth conditions of CdTe crystals from Te-rich melts without Cd source the axial distribution of the free holes along the ingots is increasing from 10 14 cm -3 at the first-to-freeze region up to 10 16 cm -3 at the crystal end. Benz [2] we showed that under uncontrolled growth conditions of CdTe crystals from Te-rich melts without Cd source the axial distribution of the free holes along the ingots is increasing from 10 14 cm -3 at the first-to-freeze region up to 10 16 cm -3 at the crystal end.…”

Direct evidence of enhanced chlorine segregation at grain boundaries in polycrystalline CdTe thin films via three‐dimensional TOF‐SIMS imaging

“…Information about the role of chlorine impurities in the grain interiors can be found in the single‐crystal CdTe and CdTe : Cl work that has been completed for the gamma‐ray detector field. An isolated Cl Te ′ defect would act as a shallow donor, whereas an increase of chlorine content in the crystal leads to increased material resistivity (presumably because of the formation of defect complexes with V Cd ●● acceptors) . However, as in the polycrystalline material, these Cl Te ′ defects tend to form defect complexes with cadmium vacancies that eliminate a deep‐level defect and would improve PV performance .…”

“…Even in the previous works, the exact mechanism for this increase was not yet firmly established; however, it is generally believed that this is the result of eliminating deep‐level traps, especially at the grain boundaries . This is commonly explained by the formation of the shallow—relative to the valance‐band maximum—defect clusters involving chlorine (( V Cd ●● 2Cl Te ′) x , or the A‐center ( V Cd ●● Cl Te ′) ● ), which would passivate V Cd ●● deep‐level defects .…”