What do nonlinear optical spectroscopy and picosecond photinduced absorption have to say about excited states in conjugated polymers?

We present a self-consistent picture of the excited state energy spectrum of poly(para-phenylene vinylene) based on theoretical calculations of exicted states and and experimental electroabsorption (EA) and picosecond photoinduced absorption measurements (PA). Our calculations place the one electron—one hole continuum (nBu) at 0.9 ± 0.2 eV above the 1Bu exciton. This is in agreement with EA and ps PA in the i.r., which finds an even-parity exciton (the mAg) about 0.7 eV away from the 1Bu. The high energy ps PA at 1.5–1.7 eV is to a biexciton whose energy is consistent with our estimates.