Enhanced Rectification of Lanthanum Hydroxide-Doped Graphene Quantum Dots/Silicon Heterostructures at Cryogenic Temperatures


Altan A. A., Berktaş Z., Kaymak N., YILDIZ M., Bartolomeo A. D., ORHAN E.

Micro and Nano Letters, cilt.20, sa.1, 2025 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Kısa Makale
  • Cilt numarası: 20 Sayı: 1
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1049/mna2.70012
  • Dergi Adı: Micro and Nano Letters
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, EMBASE, INSPEC, Directory of Open Access Journals
  • Anahtar Kelimeler: barrier inhomogeneity, cryogenic rectification, graphene quantum dots, heterojunction, lanthanum hydroxide nanoparticles
  • Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet

Özet

This study reports the fabrication and temperature-dependent electrical characterization of a heterojunction formed by lanthanum(III) hydroxide nanoparticles doped with polyethyleneimine-functionalised nitrogen-doped graphene quantum dots (La(OH)3NPs/PEI N-GQDs) on n-type silicon (n-type Si). The heterostructure exhibits diode-like behaviour in the 77–400 K temperature range, with rectification exceeding two orders of magnitude and increasing as the temperature decreases, reaching an exceptionally high value above 10⁵ at 77 K. Temperature-dependent diode parameters, including barrier height, series resistance, and ideality factor, are extracted using the thermionic emission model, revealing that barrier height increases and ideality factor decreases with rising temperature. These trends, along with significant deviations from the ideal Richardson behaviour of Schottky diodes, are effectively explained by the Werner–Güttler model, which attributes them to Gaussian spatial inhomogeneities of the barrier arising from interface states and nanocomposite-induced fluctuations. This study highlights the robust rectifying behaviour, excellent cryogenic performance, and wide-temperature applicability of the La(OH)3NPs/PEI N-GQDs on the Si heterostructure, establishing it as a promising platform for low-power diode applications under extreme thermal conditions.