Periodic Reporting for period 3 - PAIDEIA (PlAsmon InduceD hot Electron extraction with doped semiconductors for Infrared solAr energy)
Reporting period: 2022-04-01 to 2023-06-30
The project PAIDEIA stands for "plasmon induced hot electron extraction with doped semiconductors for infrared solar energy".
Almost half of the irradiation from the Sun is not in the visible region, but in the infrared part. This portion of Sun irradiation is not absorbed by most of the commercially available photovoltaic cells, with some very expensive exceptions.
The idea of the project is to employ non-toxic nanomaterials based on Earth abundant elements that are able to absorb efficiently the infrared part of the Sun irradiation. We call these materials "doped semiconductor nanocrystals". If we create a junction between these nanomaterials and semiconductors that are also based on Earth abundant elements, as for example titanium dioxide or tin oxide, we can extract charges from the doped semiconductor nanocrystals that are photogenerated by Sun irradiation and such charges can be collected by electrodes and results in a photocurrent. This type of photovoltaic cell is based on a completely different physical phenomenon with respect to the conventional photovoltaic cells.
In the project we want to study the optical and electronic properties of the junctions based on doped semiconductor nanocrystals and semiconductors. With such junctions we want to fabricate photovoltaic cells that are able to absorb the infrared portion of the Sun irradiation. These solar cells, able to absorb portion of the Sun irradiation, will be coupled with conventional solar cells that work in the visible.
Thus, with PAIDEIA we develop a novel solution for terrestrial solar panels that will spectrally widen the exploitation of the Sun, our largest power plant.
Almost half of the irradiation from the Sun is not in the visible region, but in the infrared part. This portion of Sun irradiation is not absorbed by most of the commercially available photovoltaic cells, with some very expensive exceptions.
The idea of the project is to employ non-toxic nanomaterials based on Earth abundant elements that are able to absorb efficiently the infrared part of the Sun irradiation. We call these materials "doped semiconductor nanocrystals". If we create a junction between these nanomaterials and semiconductors that are also based on Earth abundant elements, as for example titanium dioxide or tin oxide, we can extract charges from the doped semiconductor nanocrystals that are photogenerated by Sun irradiation and such charges can be collected by electrodes and results in a photocurrent. This type of photovoltaic cell is based on a completely different physical phenomenon with respect to the conventional photovoltaic cells.
In the project we want to study the optical and electronic properties of the junctions based on doped semiconductor nanocrystals and semiconductors. With such junctions we want to fabricate photovoltaic cells that are able to absorb the infrared portion of the Sun irradiation. These solar cells, able to absorb portion of the Sun irradiation, will be coupled with conventional solar cells that work in the visible.
Thus, with PAIDEIA we develop a novel solution for terrestrial solar panels that will spectrally widen the exploitation of the Sun, our largest power plant.
In the reporting period we have performed several activities:
1) We have fabricated doped semiconductor nanocrystal / semiconductor junctions employing different zero-dimensional and two-dimensional nanomaterials.
2) We have studied the ultrafast properties of different doped semiconductor nanocrystals. The ultrafast properties of these materials are very important because the lifetime of the photogenerated charges in these materials is well below one picosecond (a millionth of a millionth of seconds). We have focussed especially on indium tin oxide nanocrystals, since this material is the most employed for the hot electron extraction in the infrared. The issue with this nanomaterial is the scarcity of indium. Thus, the substitution of indium tin oxide with other doped semiconductors is one of the key point of the project PAIDEIA. For example, we have studied copper sulfide nanoflakes that has the advantage of including only copper and sulphur, which are Earth abundant elements.
3) We have studied junctions of indium tin oxide nanocrystals with different semiconductors, such as titanium dioxide and tin oxide. We have studied the ultrafast optical properties of such junctions together with morphological analyses.
4) We have fabricated photovoltaic devices based on the above mentioned junctions. We have some promising results towards the achievement of a photocurrent in this system.
1) We have fabricated doped semiconductor nanocrystal / semiconductor junctions employing different zero-dimensional and two-dimensional nanomaterials.
2) We have studied the ultrafast properties of different doped semiconductor nanocrystals. The ultrafast properties of these materials are very important because the lifetime of the photogenerated charges in these materials is well below one picosecond (a millionth of a millionth of seconds). We have focussed especially on indium tin oxide nanocrystals, since this material is the most employed for the hot electron extraction in the infrared. The issue with this nanomaterial is the scarcity of indium. Thus, the substitution of indium tin oxide with other doped semiconductors is one of the key point of the project PAIDEIA. For example, we have studied copper sulfide nanoflakes that has the advantage of including only copper and sulphur, which are Earth abundant elements.
3) We have studied junctions of indium tin oxide nanocrystals with different semiconductors, such as titanium dioxide and tin oxide. We have studied the ultrafast optical properties of such junctions together with morphological analyses.
4) We have fabricated photovoltaic devices based on the above mentioned junctions. We have some promising results towards the achievement of a photocurrent in this system.
Results on the indium tin oxide nanocrystals/doped semiconductors junction are beyond the state of the art. Most of the photovoltaic cells based on plasmon-induced hot electron extraction are fabricated with noble metals, such as gold or silver, and not with doped semiconductors.
The fabrication of a photovoltaic cell based of such junctions is not reported in literature. Up to now, only a report on a photoelectrochemical cell based on indium tin oxide nanocrystals has been reported.
In the next months, up to the end of the PAIDEIA project, the goal is the achievement of a significant photocurrent in the near infrared with indium tin oxide nanocrystals / doped semiconductors junctions. Furthermore, this significant photocurrent is the necessary condition to build a photovoltaic cell with this junction operating in the infrared. In this way, we are willing to fabricate a tandem cell that includes the infrared solar cell developed in the project PAIDEIA and a commercially available visible solar cell. The tandem solar cell will absorb most of the Sun irradiation in the visible and in the infrared.
Another important aspect is the substitution of indium tin oxide, with the drawback of the scarcity of indium, with doped semiconductors that include only Earth abundant materials, like for example copper chalcogenides.
The fabrication of a photovoltaic cell based of such junctions is not reported in literature. Up to now, only a report on a photoelectrochemical cell based on indium tin oxide nanocrystals has been reported.
In the next months, up to the end of the PAIDEIA project, the goal is the achievement of a significant photocurrent in the near infrared with indium tin oxide nanocrystals / doped semiconductors junctions. Furthermore, this significant photocurrent is the necessary condition to build a photovoltaic cell with this junction operating in the infrared. In this way, we are willing to fabricate a tandem cell that includes the infrared solar cell developed in the project PAIDEIA and a commercially available visible solar cell. The tandem solar cell will absorb most of the Sun irradiation in the visible and in the infrared.
Another important aspect is the substitution of indium tin oxide, with the drawback of the scarcity of indium, with doped semiconductors that include only Earth abundant materials, like for example copper chalcogenides.