We describe a general synthesis of conductive gold thin films doped with entrapped organic molecules,
and demonstrate, for the first time, the immobilization of a redox couple within an electrode in a single
step. The resulting film is of dual properties: conductivity arising from the gold, and redox behavior
originating from the entrapped molecule. Faster electron-transfer rates are found for the entrapped
case, compared to adsorption. The conductivity of the film affects the organic molecule–metal interactions,
as seen in resistivity measurements, in Raman spectroscopy of the metal-entrapped molecules and from
a remarkable red shift of 30 nm in emission spectroscopy. Doping is found to affect the work function
of gold. Thin conductive doped metal films are of relevance to a variety of applications such as
electrochemical detectors, electrode materials for electrochemical impedance spectroscopy, micro and
nano electronics interconnects for packaging and for printed circuit boards. The ability to fine-tune the
work function opens the possibility to design the desired energy level gaps for optoelectronic applications
such as light emitting diodes (LEDs), solar cells and transistors.
conductive_molecularly_doped_gold_films.pdf conductive_molecularly_doped_gold_films.pngIn recent years, hybrid organic–inorganic perovskite light absorbers have attracted much
attention in the field of solar cells due to their optoelectronic characteristics that enable high power
conversion efficiencies. Perovskite-based solar cells’ efficiency has increased dramatically from
3.8% to more than 20% in just a few years, making them a promising low-cost alternative for
photovoltaic applications. The deposition of perovskite into a mesoporous metal oxide is an
influential factor affecting solar cell performance. Full coverage and pore filling into the porous metal
oxide are important issues in the fabrication of highly-efficient mesoporous perovskite solar cells.
In this work, we carry out a structural and quantitative investigation of CH3NH3PbI3 pore filling
deposited via sequential two-step deposition into two different mesoporous metal oxides—TiO2
and Al2O3. We avoid using a hole conductor in the perovskite solar cells studied in this work to
eliminate undesirable end results. Filling oxide pores with perovskite was characterized by Energy
Dispersive X-ray Spectroscopy (EDS) in Transmission Electron Microscopy (TEM) on cross-sectional
focused ion beam (FIB) lamellae. Complete pore filling of CH3NH3PbI3 perovskite into the metal
oxide pores was observed down to X-depth, showing the presence of Pb and I inside the pores.
The observations reported in this work are particularly important for mesoporous Al2O3 perovskite
solar cells, as pore filling is essential for the operation of this solar cell structure. This work presents
structural and quantitative proof of complete pore filling into mesoporous perovskite-based solar
cells, substantiating their high power conversion efficiency.
structural_and_quantitative_investigation_of.png structural_and_quantitative_investigation_of.pdfHybrid perovskite and all-inorganic perovskite have attracted much attention
in recent years owing to their successful use in the photovoltaic field.
Usually the perovskite is used in its bulk form, although recently, perovskites’
nanocrystalline form has received increased attention. Recent developments
in the evolving research field of nanomaterial-based perovskite are reviewed.
Both hybrid organic-inorganic and all-inorganic perovskite nanostructures are
discussed, as well as approaches to tune the optical properties by controlling
the size and shape of perovskite nanostructures. In addition, chemical modifications
can change the perovskite nanostructures’ band-gap, similar to their
bulk counterpart. Several applications, including light-emitting diodes, lasers,
and detectors, demonstrate the latent potential of perovskite nanostructures.
inorganic_and_hybrid_organo-metal_perovskite.pdf