Summary Transition metal oxides/silicon heterocontact solar cells are the subject of intense research efforts owing to their simpler processing steps and reduced parasitic absorption as compared with the traditional silicon heterostructure counterparts. Recently, molybdenum oxide (MoOx, x < 3) has emerged as an integral transition metal oxide for crystalline silicon (cSi)‐based solar cell based on carrier‐selective contacts (CSCs). In this paper, we physically modelled the CSC‐based cSi solar cell featuring MoOx/intrinsic a‐Si:H/n‐type cSi/intrinsic a‐Si:H/n+‐type a‐Si:H for the first time using Silvaco technology computer‐aided design simulator. To analyse the optical and electrical properties of the proposed solar cell, several technological parameters such as work function and thickness of MoOx contact layer, intrinsic a‐Si:H band gap, interface recombination, series resistance, and temperature coefficient have been evaluated. It has been shown that higher work function of MoOx induces the formation of a favourable Schottky barrier height as well as an inversion at the front interface, stimulating least resistive path for holes. Utilising thinner MoOx layer implies reduced tunnelling of minority charge carriers, thus enabling the device to numerically attain 25.33% efficiency. With an optimised interface recombination velocity and reduced parasitic absorption, the proposed device exhibited higher Voc of 752 mV, Jsc of 38.8 mA/cm2, fill‐factor of 79.0%, and an efficiency of 25.6%, which can be termed as the harbinger for industrial production of next‐generation efficient solar cell technology.

The rational combination of tetracene (Tc) with crystalline silicon (c-Si) could greatly enhance c-Si solar cell efficiencies via singlet fission. The Tc/c-Si energy-level alignment (ELA) is thought to be central to controlling the required interface transfer processes. We modified hydrogen-terminated c-Si (H-Si) with 2,2′-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6TCNNQ), C60, or NF3 and probed the effect on the c-Si surface chemistry, the Tc/c-Si ELA, the Tc morphology, and solar cell characteristics using ultraviolet and X-ray photoelectron spectroscopy, atomic force microscopy, X-ray diffraction, photoluminescence transients, device measurements, and transfer matrix-optical modelling.Sub-monolayer interlayers of F6TCNNQ shifted the Tc/H-Si(111) ELA by up to 0.55 eV. C60 showed no notable effect on the ELA and proved detrimental for the Tc film morphology and solar cell performance. Neither F6TCNNQ nor C60 improved the Tc-related photocurrent significantly.NF3 CVD substituted the H-termination of H-Si(100) with more electronegative species and resulted in work functions as high as 6 eV. This changed the Tc/H-Si(100) ELA by up to 0.45 eV. NF3 plasma from a remote source caused pronounced c-Si oxidation and a diminished c-Si photoluminescence lifetime, which was not observed for NF3 plasma created in close proximity to the c-Si surface or neutral NF3. We discuss possible reasons for why the improved ELA does not lead to an improved singlet fission harvest.

Thin films of transition metal oxides such as molybdenum oxide (MoOx) are attractive for application in silicon heterojunction solar cells for their potential to yield large short‐circuit current density. However, full control of electrical properties of thin MoOx layers must be mastered to obtain an efficient hole collector. Here, we show that the key to control the MoOx layer quality is the interface between the MoOx and the hydrogenated intrinsic amorphous silicon passivation layer underneath. By means of ab initio modelling, we demonstrate a dipole at such interface and study its minimization in terms of work function variation to enable high performance hole transport. We apply this knowledge to experimentally tailor the oxygen content in MoOx by plasma treatments (PTs). PTs act as a barrier to oxygen diffusion/reaction and result in optimal electrical properties of the MoOx hole collector. With this approach, we can thin down the MoOx thickness to 1.7 nm and demonstrate short‐circuit current density well above 40 mA/cm2 and a champion device exhibiting 23.83% conversion efficiency.

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