An experimental study of band gap states electrical properties in poly‐Si TFTs by the analysis of the transient currents

Michalas, Loukas; Papaioannou, George; Kouvatsos, Dimitrios N.; Voutsas, Apostolos T.

doi:10.1002/pssc.200780166

Cited by 5 publications

(2 citation statements)

References 12 publications

(25 reference statements)

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“…Studies analyzing the DOS distribution of oxide semiconductors using light have been conducted using various methods [18][19][20][21][22]. Several research groups have reported the threshold voltage shift and subthreshold voltage swing (S/S) slope of oxide TFT as a function of light intensity [23][24][25]. The donor-like states of oxide semiconductors have also been studied as a characteristic of photocurrent changes depending on the wavelength of light [26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Donor-like State Distributions in Solution-Processed IZO Thin-Film Transistor through Photocurrent Analysis

Kim,

Lee,

Ejderha

et al. 2023

Nanomaterials

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The density of donor-like state distributions in solution-processed indium–zinc-oxide (IZO) thin-film transistors (TFTs) is thoroughly analyzed using photon energy irradiation. This study focuses on quantitatively calculating the distribution of density of states (DOS) in IZO semiconductors, with a specific emphasis on their variation with indium concentration. Two calculation methods, namely photoexcited charge collection spectroscopy (PECCS) and photocurrent-induced DOS spectroscopy (PIDS), are employed to estimate the density of the donor-like states. This dual approach not only ensures the accuracy of the findings but also provides a comprehensive perspective on the properties of semiconductors. The results reveal a consistent characteristic: the Recombination–Generation (R-G) center energy ET, a key aspect of the donor-like state, is acquired at approximately 3.26 eV, irrespective of the In concentration. This finding suggests that weak bonds and oxygen vacancies within the Zn-O bonding structure of IZO semiconductors act as the primary source of R-G centers, contributing to the donor-like state distribution. By highlighting this fundamental aspect of IZO semiconductors, this study enhances our understanding of their charge-transport mechanisms. Moreover, it offers valuable insight for addressing stability issues such as negative bias illumination stress, potentially leading to the improved performance and reliability of solution-processed IZO TFTs. The study contributes to the advancement of displays and technologies by presenting further innovations and applications for evaluating the fundamentals of semiconductors.

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Section: Introductionmentioning

confidence: 99%

Investigation of Donor-like State Distributions in Solution-Processed IZO Thin-Film Transistor through Photocurrent Analysis

Kim,

Lee,

Ejderha

et al. 2023

Nanomaterials

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“…Στη δεύτερη περίπτωση που αντιστοιχεί σε θετικό σήμα, η μέτρηση πραγματοποιείται μετά τη μετάβαση της πύλης από ισχυρή σε ασθενή αναστροφή (undershoot)[77]. Το σήμα στη περίπτωση αυτή οφείλεται στη σταδιακή εκπομπή των ηλεκτρονίων από καταστάσεις στο πάνω μισό του ενεργειακού χάσματος[95]. Φάσματα DLTS για διατάξεις σε υμένια 30nm Σχήμα 7.10: Φάσματα DLTS για διατάξεις σε υμένια 50nm Σχήμα 7.11: Φάσματα DLTS για διατάξεις σε υμένια 100nm πάχους 30 nm με προσανατολισμό πύλης που επιβάλλει τη κίνηση των φορέων παράλληλα στη διεύθυνση των φραγμών δυναμικού.Όπως απεικονίζεται στο σχήμα 8.2 η δημιουργία κενών πυριτίου εντοπίζεται εντονότερη προς τη πίσω διεπιφάνεια του υλικού ενώ αρκετά σημαντική και η δημιουργία κενών οξυγόνου στο διηλεκτρικό της πύλης.…”

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Μελέτη Των Ηλεκτρικών Ιδιοτήτων Διατάξεων Λεπτού Υμενίου

Michalas¹,

Μιχαλάς²

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Κεφάλαιο 2 Άμορφο και πολυκρυσταλλικό πυρίτιο 2.1 Εισαγωγή 27 2.2.1 Το Άμορφο Πυρίτιο 27 2.2.2 Το ενεργειακό χάσμα του a-Si 28 2.2.3 Ηλεκτρικές ιδιότητες 31 2.3.1 Το Πολυκρυσταλλικό Πυρίτιο 34 2.3.2 Το ενεργειακό χάσμα του poly-Si 35 2.3.3 Ηλεκτρικά χαρακτηριστικά

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Limits to model amphoteric defect recombination via SRH statistics

Steingrube

Brendel

Altermatt

2011

Physica Status Solidi (a)

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In semiconductor device modeling, it is common practice to approximate recombination via amphoteric defects by means of the Shockley-Read-Hall (SRH) theory. We show by means of a mathematically rigorous treatment that this approximation is only justified if: (i) the defect distribution of amphoteric defects is approximated by two equally-shaped energy distributions of acceptor-and donor-like defect states which are separated in energy by the effective correlation energy, (ii) the ratios of the capture cross-sections (CCS) of free carriers for charged and neutral defect states are strongly asymmetric, (iii) the correlation energy is positive, and (iv) the defect density has its maximum between the quasi-Fermi levels (QFLs) for the trapped carriers (TQFLs). In particular, we investigate this kind of SRH approximation for the case of injection-dependent recombination at the interface between crystalline silicon (c-Si) and amorphous silicon (a-Si:H), a system that has recently been used to passivate the surface of Si solar cells. It is shown that care must be taken when applying this SRH approximation at low excess carrier densities Dn, e.g., at pn-junctions between a-Si:H and c-Si or at low illumination levels, because the defect distributions may peak outside the TQFLs. We apply a selfconsistent model, which includes the band bending in c-Si caused by both light-induced, trapped charges in the a-Si:H layer and at the a-Si/c-Si interface. We show that these trapped charges significantly influence the recombination rate and should be taken into account, as opposed to common practice.

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An experimental study of band gap states electrical properties in poly‐Si TFTs by the analysis of the transient currents

Cited by 5 publications

References 12 publications

Investigation of Donor-like State Distributions in Solution-Processed IZO Thin-Film Transistor through Photocurrent Analysis

Investigation of Donor-like State Distributions in Solution-Processed IZO Thin-Film Transistor through Photocurrent Analysis

Μελέτη Των Ηλεκτρικών Ιδιοτήτων Διατάξεων Λεπτού Υμενίου

Limits to model amphoteric defect recombination via SRH statistics

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