Niobium-doped NiO as p-type nanostructured layer for transparent photovoltaics

Anion and Cation Co-doping of NiO for Transparent Photovoltaics and Smart Window Applications

“…In a previous investigation we have shown that nitrogen doping in NiO can improve its transparency by minimizing structural disorder, energy band gap widening [18] and reduction of mid-band-gap states [19]. In addition, it was revealed that p-type Nb-doped NiO can exhibit photovoltaic behaviour when forming a p/n junction with mesoporous TiO2 [7]. In this work, we proceeded in a combinatorial and selective double doping of NiO in an attempt to enhance further the photovoltaic output characteristics of the transparent NiO/TiO2 heterostructure.…”

“…The rf-sputtered NiO layer was co-doped with the optimum amounts of anion (nitrogen -N) and cation (niobium -Nb) dopants. The fabricated heterojunction formed with mesoporous TiO2 showed excellent NiO:(Nb,N)/TiO2 UV-PV behaviour with enhanced characteristics compared to the device where the NiO layer was single-doped (NiO:Nb/TiO2) [7]. Material improvements and modifications of the fabrication procedure of the NiO:(Nb,N)/TiO2 heterojunction for potential smart windows, transparent electronic and photonic applications are also addressed.…”

“…Nickel oxide (NiO) is the most commonly used p-type oxide and, provided it can be sufficiently transparent, it has been used with transparent n-type oxides like In2O3:Sn (ITO), ZnO and TiO2 to form a p/n junction and realize solar-blind devices absorbing the ultraviolet solar radiation. All-oxide NiO-based ultraviolet photovoltaics (UV-PVs) have been reported for NiO/TiO2 [5][6][7][8][9] and NiO/ZnO [10][11][12][13][14]. As in the case of conventional PVs, the main factors determining the conversion efficiency are: (i) the efficient absorption of photons at the front illuminated surface and generation of carriers, (ii) the efficient separation and transfer of these photogenerated carriers across the device with the aid of the built-in electrostatic field at the interface and (iii) the collection of the photogenerated carriers at the respective electrodes.…”

“…For the case of NiO/TiO2 UV-PVs, improvements in the performance of the devices have been achieved by following some of the above mentioned techniques. For example, heat treatments up to 600 o C have been employed [9,11], dopants like N in TiO2 [6] or Nb in NiO [7] have been used or suitable interlayers have been inserted at the NiO-TiO2 interface like SnS or MgO [16,17] so to enhance the output characteristics of the UV-PVs.…”

On the Fragmentation of Ni(II) β-Diketonate-Diamine Complexes as Molecular Precursors for NiO Films: A Theoretical and Experimental Investigation

“…Nanomaterials based on NiO, a multi-functional p-type semiconductor with a wide band gap (3.5 eV) [1], have been the object of numerous studies in view of their various technological end-uses, among which are electrochromic devices [2][3][4][5][6][7], solar cells [8][9][10][11][12], gas sensors [13][14][15][16][17], and heterogeneous catalysts for a variety of processes [18][19][20][21][22][23][24][25][26]. This wide perspective of attractive utilization has triggered interest in their preparation by different strategies [1], among which sol-gel and chemical vapor deposition (CVD) [27][28][29], that are endowed with several degrees of freedom to tailor material structure, chemical composition, and morphology.…”