Simone Casaluci

Solid-state solar modules based on mesoscopic organometal halide perovskite: a route towards the up-scaling process

We fabricated the first solid state modules based on organometal halide perovskite CH3NH3PbI3-xClx using Spiro-OMeTAD and poly(3-hexylthiophene) as hole transport materials. Device up-scaling was performed using innovative procedures to realize large-area cells and the integrated series-interconnections. The perovskite-based modules show a maximum conversion efficiency of 5.1% using both poly(3-hexylthiophene) and Spiro-OMeTAD. A long-term stability test was performed (in air, under AM1.5G, 1 Sun illumination conditions) using both materials showing different behaviour under continuous light stress. Whilst the poly(3-hexylthiophene)-based module efficiency drops by about 80% with respect to the initial value after 170 hours, the Spiro-based module shows a promising long-term stability maintaining more than 60% of its initial efficiency after 335 hours.

Fabrication and Characterization of Mesoscopic Perovskite Photodiodes

Mesoscopic photodiodes were fabricated with hybrid organic/inorganic perovskite as absorber layer and Spiro-OMeTAD as hole transport Layer. The perovskite layer was grown using a two-step deposition technique. Our photodiode in addition to a good rectification behavior (three orders of magnitude, range -1 to 1 V) shows a small noise current (<; 1 pA/(Hz)1/2), a high responsivity value (0.35 A/W) at 500 nanometers, and a good spectral response in the entire visible range. The Bode analysis shows a bandwidth of 108 KHz.

High efficient perovskite solar cells by employing zinc-phthalocyanine as hole transporting layer

This work presents, a new efficient structure for mesoscopic organometal halide perovskite based solar cells (PSCs) employing vacuum evaporated zinc-phthalocyanine as hole transporting layer. The proposed device structure overcame 8% in efficiency and it is promising in term of stability and low cost manufacturing process.

Perovskite solar cells stabilized by carbon nanostructure-P3HT blends

We present the use of covalently functionalized carbon nanostructures (CNSs) such as single-wall carbon nanotubes (SWCNTs) and graphene nanoplatelets (GNPs), as conductive nanofillers in a P3HT matrix. We propose a simple approach for the preparation of the active blends used as hole transport layer (HTL) in mesoporous perovskite solar cells (PSCs). We demonstrate that for both SWCNT and GNP nanofillers, power conversion efficiencies (~10%) and shelf life stabilities (over 3240 hours) are improved with respect to PSCs using bare P3HT as the HTL.

Mesoscopic perovskite solar cells and modules

In this work we exploit the use of a new promising class of light harvesting materials, namely the hybrid organic halide perovskites (CH3NH3PbI3-xClx), for the fabrication of mesoscopic perovskite solar cells and series-connected monolithic perovskite module. To achieve this goal, important innovative procedures were implemented in order to define a reproducible fabrication path applicable also to large area devices. Small area solar cells were fabricated with both Spiro-OMeTAD and the P3HT polymer as Hole Transporting Material (HTM) both showing a Power Conversion Efficiency (PCE) up to 10.5%. First attempts to scale up the size of the cell to a module size shown a PCE of 5.1% on an active area of 13.44cm2. In order to improve the efficiency of the module, we developed a new Laser assisted patterning of the perovskite/compact layers together with an optimized perovskite deposition in controlled atmosphere. This allowed us to improve the module PCE up to 7.3% which represent the state of art efficiency for a perovskite module. A promising long-term stability was obtained for the module with Spiro-OMeTAD as HTM. Supporting simulations of Mesoscopic Perovskite Solar Cells were obtained by using the multiscale device simulator TiberCAD.

Perovskite and a-Si:H/c-Si tandem solar cell

In this work the fabrication of Perovskite/Si tandem-solar cell is reported and discussed. In principle this configuration allows cell efficiency higher than single c-Si junction. While Perovskite cell was used as top cell, a-Si:H/c-Si heterojunction was adopted as a bottom cell. The investigated process starts from Glass/FTO/c-TiO2/n-TiO2/CH3NH3PbI3/ Spiro-OMeTAD/ITO top cell, coupled to an ITO/a-Si:H/c-Si/back reflector/Al heterojunction bottom cell. ITO film is used to join the top and bottom cell. Preliminary results demonstrate the feasibility of the tandem cell, indeed Voc value as high as 1.65mV has been achieved. Numerical simulations is used to evaluate the limit and the potentiality of the proposed tandem structure.

Fabrication and characterization of printed perovskite-based photodiodes

We fabricated the first perovskite-based photodiodes using one-step and two-step deposition with Spiro-OMeTAD as Hole Transport Material (HTM). Our photodiode show excellent rectification behavior, low dark currents under reverse bias and good dynamic properties evaluated with Bode and eye diagram. A frequency resolved noise analysis was performed in order to extract detectivity and optimal bias potential values.