Enhanced photovoltaic response of organic solar cell by singlet-to-triplet exciton conversion

Abstract

Ir complex was doped to conjugated polymers, and the photoinduced absorption of triplet excitons in host materials was examined. A greatly enhanced intersystem crossing rate was observed, despite the decrease in triplet exciton lifetime. The authors find that the steady-state triplet exciton population in host polymer would increase by an order of magnitude. Conjugated polymer/colloidal CdSe nanocrystal hybrid solar cells were fabricated and the effect of Ir-complex doping on photovoltaic response was studied. It was found that due to the enhanced singlet-to-triplet conversion, greatly enhanced photovoltaic response of these hybrid organic solar cells was observed. The results suggest that triplet solar cells may be achieved by doping conventional photovoltaic materials with transition-metal complexes.

Conjugated Silicon–Based Polymer Resists for Nanotechnologies: EB and UV Meditated Degradation Processes in Polysilanes

“…11), or for the investigation of triplet harvester organic solar cells. 12) As the polysilanes are an important group of materials with prospective applications, the comparison of PL and CL and disclosing similarities and differences in the excitation, degradation and metastability is an important question. The excitation by EB is different and in consequences similar to injection of a pair of carriers, where excitons are generated after coupling in an electron-hole pair.…”

“…Ã Þ, and their long wavelength bands are frequently discussed topics due to their potential applications in both LEDs 18) and in the connection to the triplet photon harvesting in solar cells, 12) though the latter one with some ambiguity in explanation. 19 20) We suggested 3) a model based on the Frenkel type exciton, sensitive to the excitation wavelength, creating both DB and WB for short wavelength (266 nm), and removing defects at long wavelength (355 nm) of excitation.…”

Les cellules photovoltaïques organiques

“…Enfin, il est possible d'augmenter la durée de vie des excitons en favorisant la conversion des singulets (S) en triplets (T) qui présentent une valeur de τ plus grande, pouvant atteindre quelques millisecondes [10]. Les excitons singulets sont formés par les électrons qui quittent le niveau HOMO (S 0 ) et se placent sur un niveau énergétique de type S. Par conversion intersystème, il peuvent se retrouver sur un niveau de type T, de durée de vie beaucoup plus grande.…”

Charge transport and microstructure in PFO:MEH-PPV polymer blend thin films

“…The polyfluorenes also have an additional advantage of its emission in the bluish green region. Presently, poly (9,9'-dihexyl fluorenyl-2,7-diyl) (PFO) is the most intensively investigated polymeric material for the single-layer organic electronic device applications [4][5][6]. Recent trend [7][8][9] to achieve improved efficiency is the use of single emissive layer made from the blend of polymers.…”

“…the]-V characteristic is governed by [17][18][19] (5) where] is the current density, Vis the applied voltage, q is the elementary charge, d is the thickness of the material film, p., is the hole carrier mobility, and F(x) is the electric field, N v is the effective density of states, c is the dielectric constant of material, co is permittivity of the free space. The experimental data of device A has been analyzed in terms of above equations from temperatures 100 K to 290 K as shown in Fig.…”