\u00a9 iStock\/Eloi_Omella<\/figcaption><\/figure>\nThe new concept improves efficiency and performance<\/h3>\n
\u201cThe optical and electronic properties of caesium lead iodide in its beta and gamma phase are different from each other,\u201d explained Professor Vaynzof.<\/p>\n
\u201cBy placing a gamma-perovskite on top of the beta-perovskite we were able to fabricate a phase heterojunction solar cell, that is significantly more efficient as compared to solar cells that are based on single phase perovskites.\u201d<\/p>\n
The researchers demonstrated that the top layer of gamma-phase influences the performance of photovoltaic solar cells.<\/p>\n
\u201cEven thin layers of gamma-perovskite led to a performance improvement due to the passivation of defects at the surface of the bottom layer. Thicker layers of gamma-phase resulted in significant improvement in all of the photovoltaic performance parameters with the champion device reaching a power conversion efficiency of over 20%,\u201d explained Ran Ji, the lead author of the study.<\/p>\n
\u201cAdvanced spectroscopic analysis revealed that this improvement in performance is associated with increased light absorption and the formation of an advantageous energetic alignment between the two phases,\u201d added Professor Vaynzof.<\/p>\n
Importantly, the researchers confirmed that the phase heterojunction remains stable during solar cell operation and even suppresses ion migration in the solar cell absorber, resolving a common problem for perovskite materials.<\/p>\n
Utilising the heterojunction concept for the future<\/h3>\n
To realise the phase heterojunction concept, the team used two different fabrication processes for the top and bottom layers, opening the path to the formation of other such structures in the future.<\/p>\n
Professor Vaynzof stated: \u201cWe hope that this novel concept combined with a simple fabrication route for phase heterojunctions will be applicable also to a variety of material systems in a range of electronic and optoelectronic devices.\u201d<\/p>\n
As many semiconductor classes exhibit polymorphism, the concept could pave the way to entirely new applications that operate based on phase heterojunctions.<\/p>\n","protected":false},"excerpt":{"rendered":"
Photovoltaic cells require a heterojunction to ensure sunlight is converted into electricity, but new cells cannot always form them.<\/p>\n","protected":false},"author":18,"featured_media":27329,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[24204],"tags":[628,730],"acf":[],"yoast_head":"\n
New concept for photovoltaic cells developed<\/title>\n\n\n\n\n\n\n\n\n\n\n\n\n\t\n\t\n\t\n\n\n\n\n\n\t\n\t\n\t\n