Quantum dots enhance perovskite solar cell effectivity and scalability

Perovskites are hybrid compounds constituted of steel halides and natural constituents. They present nice potential in a variety of functions, e.g. LED lights, lasers, and photodetectors, however their main contribution is in solar cells, the place they’re poised to overhaul the market from their silicon counterparts.

One of the obstacles dealing with the commercialization of perovskite solar cells is that their power-conversion effectivity and operational stability drop as they scale up, making it a problem to take care of high performance in an entire solar cell.

The downside is partly with the cell’s electron-transport layer, which ensures that the electrons produced when the cell absorbs mild will switch effectively to the gadget’s electrode. In perovskite solar cells, the electron-transport layer is made with mesoporous titanium dioxide, which reveals low electron mobility, and can be vulnerable to adversarial, photocatalytic occasions beneath ultraviolet mild.

In a brand new publication in Science, scientists led by Professor Michael Grätzel at EPFL and Dr. Dong Suk Kim on the Korea Institute of Energy Research have discovered an revolutionary method to improve the efficiency and preserve it at a excessive degree in perovskite solar cells even at massive scales. The revolutionary concept was to exchange the electron-transport layer with a skinny layer of quantum dots.

Quantum dots are nanometer-sized particles that act as semiconductors, and emit mild of particular wavelengths (colours) when they’re illuminated. Their distinctive optical properties make quantum dots ideally suited to be used in a wide range of optical functions, together with photovoltaic gadgets.

The scientists changed the titanium dioxide electron-transport layer of their perovskite cells with a skinny layer of polyacrylic acid–stabilized tin(IV) oxide quantum dots, and located that it enhanced the gadgets’ light-capturing capability, whereas additionally suppressing nonradiative recombination, an efficiency-sapping phenomenon that typically takes on the interface between the electron-transport layer and the precise perovskite layer.

By utilizing the quantum dot layer, the researchers discovered that perovskite solar cells of 0.08 sq. centimeters attained a document power-conversion effectivity of 25.7% (licensed 25.4%) and excessive operational stability, whereas facilitating the scale-up. When rising the floor space of the solar cells to 1, 20, and 64 sq. centimeters, power-conversion effectivity measured at 23.3, 21.7, and 20.6% respectively.