Hybrid solar cells from MDMO-PPV and silicon nanocrystals.
Solution-processed bulk heterojunction solar cells from silicon nanocrystals (Si NCs) and poly(3-hexylthiophene) (P3HT) have shown promising power conversion efficiencies. Here we report on an attempt to enhance the performance of Si NC-polymer hybrid solar cells by using poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as a hole conductor, which is expected to yield a higher open circuit voltage than P3HT due to its lower highest occupied molecular orbital (HOMO). Bulk heterojunction solar cells consisting of 3-5 nm silicon nanocrystals (Si NCs) and poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) have been fabricated. The properties of the hybrid Si NC/MDMO-PPV devices were studied as a function of the Si NC/MDMO-PPV weight ratio. Cells of 58 wt% 3-5 nm Si NCs showed the best overall performance under simulated one-sun AM 1.5 global illumination (100 mW cm(-2)). Compared to composite films of Si NCs and poly(3-hexylthiophene), we indeed observed an improved open circuit voltage but a lower power conversion efficiency from the Si NC/MDMO-PPV devices. The lower efficiency of Si NC/MDMO-PPV is correlated to the lower hole mobility and narrower absorption spectrum of MDMO-PPV compared to P3HT.
Department of Mechanical Engineering, University of Minnesota, 111 Church St SE, Minneapolis, MN 55455, USA. liuxx373@umn.edu
Chin-Yi
CY
Liu
Uwe R
UR
Kortshagen
D053758:Nanoparticles / Q000737:chemistry*; D016566:Organoselenium Compounds / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D011789:Quantum Theory; D012825:Silicon / Q000737:chemistry*; D012993:Solar Energy; D013876:Thiophenes / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry
D016566:Organoselenium Compounds; D011137:Polystyrenes; D013876:Thiophenes; D017971:Tin Compounds; C533756:poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); C526212:poly(3-hexyl)selenophene; C109984:indium tin oxide; D012825:Silicon