Carrier trapping and recombination in TlGaSe2 layered crystals. Issue 1 (10th September 2012)

• Record Type: Journal Article
• Authors: Grivickas, Vytautas; Odrinski, Andrei; Bikbajevas, Vitalijus; Gulbinas, Karolis
• Is Part Of: Physica status solidi. Volume 250:Issue 1(2013:Jan.)
• Page Start: 160
• Page End: 168
• Publication Date: 2012-09-10
• Subjects: Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201248363
• Languages: English
• ISSNs: 0370-1972

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>In nominally undoped layered TlGaSe₂ crystals the trapping centers have been investigated by photo‐induced current transient spectroscopy (PICTS). Five acceptor and donor traps have been detected. Quite large magnitudes of capture cross‐sections for donor traps at 0.23 and 0.45 eV have been determined. The depth‐resolved free‐carrier absorption (FCA) technique has been applied for the investigation of the majority hole lifetime, <italic>τ</italic>_R, at 295 and 77 K. The pronounced <italic>τ</italic>_R reduction with increasing injection level is attributed to the trapping effect of the minority electrons which provides a way of estimating trap centers concentration. A moderate <italic>τ</italic>_R variation across layer planes is observed but no carrier diffusion related to the recombination on the external crystal surfaces is detected. Moreover, abnormally sharp <italic>τ</italic>_R drop is found for carrier concentration above 10¹⁷ cm⁻³. The possibility of excess hole and electron special separation due to compositional stacking faults and the successive their enhanced recombination at high excess carrier concentrations is discussed.</p> </abstract>