For this thesis the effects of strain on excitons in organic thin film semiconductors is investigated.A hollow-capillary pen writing technique was used to create highly ordered thin films depositedon a flexible substrate. Metal-free octabutoxy-phthalocyanine (H2OBPc) was chosen for thisstudy because it forms long chains of molecules with strong π −π interactions. Absorbance andlinear dichroism measurements were performed on films with varying levels of strain applied alongthe stacking axis, with the total strain averaging 8%. A k-vector study was also conducted toinvestigate whether the molecular stacking angle is changing due to strain. It was hypothesizedthat strain applied along the stacking axis would cause a peak shift in the absorbance spectrum,and could potentially cause a shift in the molecular stacking angle of each molecule relative tothe substrate. Red-shifting of the exciton peaks was observed in both the absorbance and lineardichroism spectra. An overall reduction in the linear dichroism was observed regardless of theincident angle in the k-vector study, indicating that the molecular stacking angle is changing
