The present invention relates to a polymer, an organic solar cell comprising the polymer, and a perovskite solar cell comprising the polymer. The polymer according to the present invention has excellent absorption ability for visible light and an energy level suitable for the use as an electron donor compound in a photo-active layer of the organic solar cell, thereby increasing the light conversion efficiency of the organic solar cell. In addition, the polymer according to the present invention has high hole mobility, and is used as a compound for a hole transport layer, and thus can improve efficiency and service life of the perovskite solar cell without an additive.

A semi-transparent perovskite-based photovoltaic cell (or solar cell), wherein the photoactive perovskite layer includes at least one polysaccharide-based inert polymer in an amount ranging between 0.5% by weight and 3.5% by weight, preferably ranging between 1% by weight and 3% by weight, more preferably ranging between 1.5% by weight and 2.8% by weight, with respect to the total weight of the perovskite precursors. The semi-transparent perovskite-based photovoltaic cell (or solar cell) can be advantageously used in various applications that require the production of electricity through the exploitation of light energy, in particular solar radiation energy such as, for example: building integrated photovoltaic (BIPV) systems; photovoltaic windows; greenhouses; photo-bioreactors; noise barriers; lighting; design; advertising; automotive industry. Said semi-transparent perovskite-based photovoltaic cell (or solar cell) can be used either in a “stand alone” mode or in modular systems.

A semi-transparent perovskite-based photovoltaic cell (or solar cell), wherein the photoactive perovskite layer includes at least one polysaccharide-based inert polymer in an amount ranging between 0.5% by weight and 3.5% by weight, preferably ranging between 1% by weight and 3% by weight, more preferably ranging between 1.5% by weight and 2.8% by weight, with respect to the total weight of the perovskite precursors. The semi-transparent perovskite-based photovoltaic cell (or solar cell) can be advantageously used in various applications that require the production of electricity through the exploitation of light energy, in particular solar radiation energy such as, for example: building integrated photovoltaic (BIPV) systems; photovoltaic windows; greenhouses; photo-bioreactors; noise barriers; lighting; design; advertising; automotive industry. Said semi-transparent perovskite-based photovoltaic cell (or solar cell) can be used either in a “stand alone” mode or in modular systems.

A photoelectric conversion element includes a base, a first electrode on or above the base, an electron-transporting layer on or above the first electrode, a photoelectric conversion layer on or above the electron-transporting layer, a hole-transporting layer on or above the photoelectric conversion layer, and a second electrode on or above the hole-transporting layer. The photoelectric conversion element has a penetration portion penetrating the electron-transporting layer and the photoelectric conversion layer. The photoelectric conversion element includes, in the penetration portion, a material of the hole-transporting layer and a material of the second electrode.

A photoelectric conversion element includes a base, a first electrode on or above the base, an electron-transporting layer on or above the first electrode, a photoelectric conversion layer on or above the electron-transporting layer, a hole-transporting layer on or above the photoelectric conversion layer, and a second electrode on or above the hole-transporting layer. The photoelectric conversion element has a penetration portion penetrating the electron-transporting layer and the photoelectric conversion layer. The photoelectric conversion element includes, in the penetration portion, a material of the hole-transporting layer and a material of the second electrode.

The process comprises treating 90-190 g titanium (IV) chloride in 10-100 ml de-ionized water for preparing Titanium cation (Ti.sup.4+); treating 130-275 ml potassium persulfate in 10-100 ml double-distilled water and keeping at constant temperature to obtain sulphate/oxide; dipping substrates into titanium (IV) chloride solution and re-dipping in de-ionized water to remove loosely bonded ions, if could be any; dipping substrates into potassium persulfate solution and re-dipping in de-ionized water to remove loosely bonded ions, if could be any, and keeping at 50-90° C. for complete one cycle; treating obtained Titanium cation (Ti.sup.4+) with sulphate/oxide and obtaining whitish layer on the substrate surface by necked eyes after about 10-15 cycles, suggesting initiation of film formation, wherein the deposition thickness of TiO.sub.2 layer is increased from 0.3-2.0-micron on determined 5-50 deposition cycles; and rinsing deposited films with de-ionized water and air annealed at 400-600° C. temperature to obtain anatase TiO.sub.2.

The process comprises treating 90-190 g titanium (IV) chloride in 10-100 ml de-ionized water for preparing Titanium cation (Ti.sup.4+); treating 130-275 ml potassium persulfate in 10-100 ml double-distilled water and keeping at constant temperature to obtain sulphate/oxide; dipping substrates into titanium (IV) chloride solution and re-dipping in de-ionized water to remove loosely bonded ions, if could be any; dipping substrates into potassium persulfate solution and re-dipping in de-ionized water to remove loosely bonded ions, if could be any, and keeping at 50-90° C. for complete one cycle; treating obtained Titanium cation (Ti.sup.4+) with sulphate/oxide and obtaining whitish layer on the substrate surface by necked eyes after about 10-15 cycles, suggesting initiation of film formation, wherein the deposition thickness of TiO.sub.2 layer is increased from 0.3-2.0-micron on determined 5-50 deposition cycles; and rinsing deposited films with de-ionized water and air annealed at 400-600° C. temperature to obtain anatase TiO.sub.2.

A solar cell according to the present disclosure includes a first electrode, a second electrode, a photoelectric conversion layer disposed between the first electrode and the second electrode, and an electron transport layer disposed between the first electrode and the photoelectric conversion layer. At least one electrode selected from the group consisting of the first electrode and the second electrode has a light-transmitting property. The photoelectric conversion layer contains a perovskite compound composed of a monovalent cation, a divalent cation, and a halogen anion. The electron transport layer contains a metal oxynitride having electron conductivity. The metal oxynitride has an electrical conductivity of greater than or equal to 1×10.sup.−7 S/cm.

Metal oxide particles have p-type semiconductivity. The metal oxide particles have a volume-based particle size distribution having a first local maximum value and a second local maximum value. The first local maximum value is in a range of 0.1 μm or more and less than 5 μm, and the second local maximum value is in a range of 5 μm or more and less than 50 μm. A ratio of the second local maximum value to the first local maximum value is 0.5 or more and less than 2.0. 99% by volume or more of the metal oxide particles have a particle diameter in a range of from 0.1 to 50 μm.

Metal oxide particles have p-type semiconductivity. The metal oxide particles have a volume-based particle size distribution having a first local maximum value and a second local maximum value. The first local maximum value is in a range of 0.1 μm or more and less than 5 μm, and the second local maximum value is in a range of 5 μm or more and less than 50 μm. A ratio of the second local maximum value to the first local maximum value is 0.5 or more and less than 2.0. 99% by volume or more of the metal oxide particles have a particle diameter in a range of from 0.1 to 50 μm.