Title:  Low-noise Stretchable Organic Photodiode using an Elastomeric Bulk Heterojunction

Committee:

Dr. Bernard Kippelen, ECE, Chair, Advisor

Dr. Omer Inan, ECE

Dr. Oliver Brand, ECE

Dr. Shyh-Chiang Shen, ECE

Dr. Pierron, Olivier, ME

Abstract: This work reports on the elastomeric bulk heterojunction having marginal mechanical property mismatch to human skin as well as tens of pico-watt noise equivalent power under different tensile strains. Our approach and results demonstrate that: (1) the detailed study on photodetector characteristics allows the photodiode using the elastomeric bulk heterojunction on a rigid substrate to yield a noise equivalent power 39 pW at 653 nm. (2) With pre-strained PEDOT:PSS/PDMS as bottom electrode and substrate, the fully stretchable organic photodiode achieves noise equivalent power values in the tens of pico-watt range and an estimated average specific detectivity value of 2.3 × 1010 Jones at 653 nm up to at least 60% strain (stretchable up to possibly 100%). (3) The freestanding film of elastomeric bulk heterojunction sustains up to 189% of tensile strain and yields Young’s modulus of tens of MPa, which is comparable to human skin. These results provide a proof-of-principle that stretchable organic photodiodes can combine the unique mechanical properties of elastomers while maintaining the remarkable performance of rigid photodetectors.