ENHANCING CONDUCTIVITY OF HOLE TRANSPORT LAYER VIA NICKEL OXIDE AND GRAPHENATED-CARBON NANOTUBES (G-CNT) COMPOSITES

Nurbahirah Norddin; Suhaidi  Shafie; Muhammad Idzdihar  Idris; Mohd Nizar  Hamidon; Fauzan  Ahmad; Xinzhi Liu

Nurbahirah Norddin Faculty of Electronics and Computer Engineering, University Technical Malaysia Melaka (UTeM), 75450 Melaka, Malaysia
Suhaidi Shafie Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Muhammad Idzdihar Idris Faculty of Electronics and Computer Engineering, University Technical Malaysia Melaka (UTeM), 75450 Melaka, Malaysia
Mohd Nizar Hamidon Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
Fauzan Ahmad Malaysia–Japan International Institute of Technology (MJIIT), Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
Xinzhi Liu Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia

Keywords: Perovskite, nickel oxide, graphenated-carbon nanotubes, electrical conductivity

Abstract

Perovskite solar cells represent a highly promising renewable energy technology due to their exceptional efficiency and cost-effectiveness. However, limitations exist in commonly used hole transport layers (HTLs) like Spiro-OMeTAD and PEDOT: PSS, which have their drawbacks. Nickel oxide (NiO) is a potential alternative HTL material but suffers from high resistivity which involves low carrier concentration, defect density, and poor charge mobility. In this study, the influence of a graphenated carbon nanotube (g-CNT) mixture on the physical, electrical, and surface morphological properties of NiO thin films was investigated. NiO:g-CNT were synthesized using a sol-gel method and characterized by field emission scanning electron microscopy (FESEM) to analyze surface morphology, X-ray diffraction (XRD) for structural properties, and energy-dispersive X-ray spectroscopy (EDX) for elemental analysis. Electrical properties were measured using a four-point probe to assess conductivity. The results revealed that incorporating 0.5 wt% g-CNT into NiO significantly reduced the resistance of the thin films from 255 kΩ to 67 kΩ. This improvement is attributed to the g-CNT’s ability to bridge grain boundaries, enhancing charge transport, even though the crystallite size was smaller compared to pristine NiO. These findings suggest that NiO could improve the performance of perovskite solar cells by enhancing their conductivity.