Abstract
Achieving full spectral response by utilizing the near-infrared (NIR) and ultraviolet (UV) parts of sunlight has undoubtedly become an important focus on increasing the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Introducing a photoluminescent conversion layer by converting NIR or UV light into visible which can be effectively utilized by perovskite photoactive layer has been considered as a very promising route. In this work, on the basis of a novel NiO/Ag/NiO transparent electrode, the NaYF4: Yb3+, Er3+/NaYF4: Yb3+, Tm3+/Ag composite layers were introduced on the backlight side of the PSCs device by the pulsed laser deposition (PLD). This design enables multi-functional effects, harvesting NIR light and converting to visible, plasmonic scattering, reflection and luminescent enhancement. In this device, we observed considerable enhancement of PCE depending strongly on the power density of sunlight. Simultaneously, acting as an efficient encapsulation layer, the device also greatly boosted the long-term stability of PSCs in ambient conditions. Furthermore, a typical UV to visible Eu(TTA)2(Phen)MAA down-conversion (DC) layer was introduced on the incident light side of PSCs, leading to improvement of PCE and light stability of PSCs. Overall, the upconversion (UC) and DC effects give rise to the highest PCE performance of 19.5% and noticeable current density (Jsc) value of 27.1 mA cm−2 among the reported transparent PSCs, suggesting the great potential for application in spectral broadening and stability enhancement of PSCs.
In this work, full spectrum response perovskite solar cells have been achieved by introducing UC and DC layer for the NIR and UV light utilization of sunlight. On the basis of the NiO/Ag/NiO transparent electrode, the efficient plasmon-enhanced NaYF4: Yb3+, Er3+/NaYF4: Yb3+, Tm3+/Ag composite layers deposited on the back side of the devices lead the PCE to be largely enhanced from 16.1% to 19.2% under 1.5 W cm−2 sunlight illumination. The PCE can be further improved to 19.5% by introducing an UV to visible DC layer (Eu(TTA)2(Phen)MAA) in the incident light side of the devices. Overall, the UC and DC effects give rise to the highest PCE performance of 19.5% and noticeable current density value of 27.1 mA cm−2 among the reported PSCs. The long-term stability and light stability have been greatly improved through the external encapsulation of the UC and DC layers, suggesting the great potential for application in spectral broadening and stability enhancement to PSCs. The present work offers a novel approach in exploiting the full spectral response of PSCs and demonstrates application potential for photovoltaic family under constant and concentrated sunlight conditions. [Display omitted]
•The NiO/Ag/NiO transparent electrodes with best transmittance and sheet resistance were prepared.•The upconversion layers lead the PCE to be largely improved from 16.1% to 19.2% under 1.5 W cm-2 sunlight illumination.•An Eu(TTA)2(Phen)MAA down-conversion layer results in an PCE of 19.5%.•This is the first attempt to convert both NIR and UV light into visible range and help to broaden the absorption scope of the PSCs.•The long-term and light stability of PSCs have been greatly improved.