Effect of RF Magnetron Sputtered Nickel Oxide Thin Films as an Anode Buffer Layer in a P₃HT:PCBM Bulk Hetero-Junction Solar Cells

Abstract

Bulk heterojunction solar cells were investigated using poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61 butyric acid methyl ester (PCBM) with a nickel oxide (NiO) anode buffer layer between the photoactive layer and an indium tin oxide (ITO) anode layer. The NiO anode buffer layer was deposited using radio frequency magnetron sputtering on an ITO electrode layer for effective hole transport and electron blocking. The NiO film is a p-type semiconductor with resistivity of 0.35 Ω cm. The power conversion efficiency was improved substantially by the NiO anode buffer layer compared to a solar cell with an anode buffer layer made from poly(3,4-ethylenedioxythiophene) (PEDOT):poly(styrene sulfonate) (PSS). The solar cell with a 10 nm thick NiO anode buffer layer had a power conversion efficiency of 4.71%. These results are explained by the improved charge transport across the interface between the active layer and ITO electrode.

Efficient CsPbBr3 Quantum-Dot Light-Emitting Diodes Using Sputtered NiO Films as Hole Injection Layers

“…The energy level diagram of the NiO films is summarized in Figure 3e. The HOMO and LUMO energy levels of ITO, NiO HIL, VB-FNPD and QD layers can be referred to in previous reports [20,21]. The p-type NiO thin films are wide-bandgap semiconductor materials with a HOMO energy level close to VB-FNPD, ensuring a hole transportation from VB-FNPD into NiO.…”

P3HT-based visible-light organic photodetectors using PEI/PAA multilayers as a p-type buffer layer

“…The C 1 of the device using NiO x is slightly higher than that of the device using PEDOT:PSS because the holes transported from the active layer to the electrode are accumulated at the NiO x /P3HT interface due to the potential barrier created by NiO x having a deeper highest occupied molecular orbital (HOMO) (5.4 eV) than the HOMO of P3HT (5.0 eV). 42,43 As a result, weak band bending occurs in the downward direction at the NiO x /P3HT interface and the holes are transferred from the HOMO of P3HT to the electrode through the HOMO of NiO x . This process is illustrated in Fig.…”

Evaluating Materials Design Parameters of Hole-Selective Contacts for Silicon Heterojunction Solar Cells

“…Additionally, it has been reported by numerous studies that increasing O 2 flow during sputter growth reduces resistivity (i.e., increases conductivity) in p-type NiO x [43], [50]- [53]. Some reports indicate an increase in hole doping and decrease in mobility [52], [53], but trends and magnitudes are inconsistent [43], [51]. Interfacial defect density D it is left as a modeled parameter.…”