1 research outputs found
Ag Doping of Organometal Lead Halide Perovskites: Morphology Modification and p‑Type Character
We report a simple
synthetic approach to grow uniform CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> perovskite (PSK) layers free of pinholes
via varied portions of silver iodide (AgI) added to the precursor
solution. XRD/EDS elemental mapping experiments demonstrated nearly
uniform Ag distribution inside the perovskite film. When the 1% AgI-assisted
perovskite films were fabricated into a p-i-n planar device, the photovoltaic
performance was enhanced by ∼30% (PCE increased from 9.5% to
12.0%) relative to the standard cell without added AgI. Measurement
of electronic properties using a hall setup indicated that perovskite
films show p-type character after Ag doping, whereas the film is n-type
without Ag. Transients of photoluminescence of perovskite films with
and without AgI additive deposited on glass, p-type (PEDOT:PSS), and
n-type (TiO<sub>2</sub>) contact layers were recorded with a time-correlated
single-photon counting (TCSPC) technique. The TCSPC results indicate
that addition of AgI inside perovskite in contact with PEDOT:PSS accelerated
the hole-extraction motion whereas that in contact with TiO<sub>2</sub> led to a decelerated electron extraction, in agreement with the
trend observed from the photovoltaic results. The silver cationic
dopant inside the perovskite films had hence an effect of controlling
the morphology to improve photovoltaic performance for devices with
p-i-n configuration