RSS Uni. Porto Graded morphologies and the performance of pffbt4t-2od:Pc71 bm devices using additive choice

  • Criador do t贸pico Reposit贸rio Aberto da Universidade do Porto
  • Start date
R

Reposit贸rio Aberto da Universidade do Porto

Guest
Breve resumo:
Title: Graded morphologies and the performance of pffbt4t-2od:pc71 bm devices using additive choice
Abstract: The impact of several solvent processing additives (1-chloronaphthalene, methylnaph-thalene, hexadecane, 1-phenyloctane, and p-anisaldehyde), 3% v/v in o-dichlorobenzene, on the performance and morphology of poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3鈥 鈥 鈥-di(2-octyldodecyl)-2,2鈥,5鈥,22033,5鈥 鈥,2鈥 鈥 鈥-quaterthiophen-5,5鈥 鈥 鈥-diyl)] (PffBT4T-2OD):[6,6]-phenyl-C71-butyric acid methyl ester (PC71 BM)-based polymer solar cells was investigated. Some additives were shown to enhance the power conversion efficiency (PCE) by ~6%, while others decreased the PCE by ~17-25% and a subset of the additives tested completely eliminated any power conversion efficiency and the operation as a photovoltaic device. Grazing-Incidence Wide Angle X-ray Scattering (GIWAXS) revealed a clear stepwise variation in the crystallinity of the systems when changing the additive between the two extreme situations of maximum PCE (1-chloronaphthalene) and null PCE (hexadecane). Small-Angle Neutron Scattering (SANS) revealed that the morphology of devices with PCE ~0% was composed of large domains with correlation lengths of ~30 nm, i.e., much larger than the typical exciton diffusion length (~12 nm) in organic semiconductors. The graded variations in crystallinity and in nano-domain size observed between the two extreme situations (1-chloronaphthalene and hexadecane) were responsible for the observed graded variations in device performance.​



Info Adicional:
Title: Graded morphologies and the performance of pffbt4t-2od:pc71 bm devices using additive choice Abstract: The impact of several solvent processing additives (1-chloronaphthalene, methylnaph-thalene, hexadecane, 1-phenyloctane, and p-anisaldehyde), 3% v/v in o-dichlorobenzene, on the performance and morphology of poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3鈥 鈥 鈥-di(2-octyldodecyl)-2,2鈥,5鈥,22033,5鈥 鈥,2鈥 鈥 鈥-quaterthiophen-5,5鈥 鈥 鈥-diyl)] (PffBT4T-2OD):[6,6]-phenyl-C71-butyric acid methyl ester (PC71 BM)-based polymer solar cells was investigated. Some additives were shown to enhance the power conversion efficiency (PCE) by ~6%, while others decreased the PCE by ~17-25% and a subset of the additives tested completely eliminated any power conversion efficiency and the operation as a photovoltaic device. Grazing-Incidence Wide Angle X-ray Scattering (GIWAXS) revealed a clear stepwise variation in the crystallinity of the systems when changing the additive between the two extreme situations of maximum PCE (1-chloronaphthalene) and null PCE (hexadecane). Small-Angle Neutron Scattering (SANS) revealed that the morphology of devices with PCE ~0% was composed of large domains with correlation lengths of ~30 nm, i.e., much larger than the typical exciton diffusion length (~12 nm) in organic semiconductors. The graded variations in crystallinity and in nano-domain size observed between the two extreme situations (1-chloronaphthalene and hexadecane) were responsible for the observed graded variations in device performance.



Autor:




Clica para continuares a ler...
 
Voltar
Topo