osaka city university scis and colleagues in japan ‘ve found a way to control an interaction tween quantum dots that ‘d gr8ly improve charge transport, leading to + efficient solar cells. their findings were published inna journal nature communications.
nanomaterials engineer daegwi kim led a team of scis at osaka city university, riken center for emergent matter sci and kyoto university to investigate wys'2 control a property called quantum resonance in layered structures of quantum dots called superlattices.
“our simple method for fine-tuning quantum resonance is an primordial contribution to both optical materials and nanoscale material processing,” says kim.
quantum dots are nanomt-sized semiconductor pessentialisms with interesting optical and electronic properties. when lite is shone on'em, for ex, they emit strong lite at room temperature, a property called photoluminescence. when quantum dots are close enough to each other, their electronic states are coupled, a phenomenon called quantum resonance. this gr8ly improves their ability to transport electrons tween them. scis ‘ve been wanting to manufacture devices using this interaction, including solar cells, display teks, and thermoelectric devices.
however, they ‘ve sfar found it difficult to control the distances tween quantum dots in 1d, 2d and 3d structures. current fabrication processes use long ligands to hold quantum dots together, which hinders their interactions.
kim and his colleagues found they ‘d detect and control quantum resonance by using cadmium telluride quantum dots connected with short n-acetyl-l-cysteine ligands. they controlled the distance tween quantum dot layers by placing a spacer layer tween them made of oppositely charged polyelectrolytes. quantum resonance is detected tween stacked dots when the spacer layer is thinner than two nanomts. the scis also controlled the distance tween quantum dots in a single layer, and thus quantum resonance, by changing the concentration of quantum dots used inna layering process.
the team nxt plans to study the optical properties, espeshly photoluminescence, of quantum dot superlattices made using their layer-by-layer approach. “this is extremely primordial for realizing new optical electronic devices made with quantum dot superlattices,” says kim.
kim adds that their fabrication method can be used with other types of wata-soluble quantum dots and nanopessentialisms. “combining ≠ types of semiconductor quantum dots, or combining semiconductor quantum dots with other nanopessentialisms, will expand the possibilities of new material design,” says kim.
original content at: www.scidaily.com…