Supplementary Information for Paper Titled

Supplementary information for paper titled

Image pixel device using integrated organic components

Fig. S1: Contact angle measurements for OctadecylPhosphonic Acid (OPA) self-assembled monolayer (SAM) formation. (a) Contact angle on glass substrate = 36˚ and (b) contact angle on SAM functionalized glass substrate = 105˚

Fig. S2: (a) Gate current measurement with OPA SAM dielectric. (b) Capacitance vs Voltage measurement for OPA SAM dielectric (Aluminum | SAM | Aluminum device structure) showing maximum specific capacitance of 0.28 μF/cm2.

Fig. S3: PulsedVgs measurement of the OFET in the integrated structure in dark (black) and under white light illumination (red) of the OPD. There is negligible variation in Ids in dark as well as under illumination which shows that the OFET is non-responsive to the wavelengths at which the OPD is monitored.

Fig. S4: Light intensity dependence in the Photovoltaic mode of a P3HT: PC71BM OPD integrated with a P3HT OFET. The semi-log plot shows a linear response due to the logarithmic dependence of Voc as a function of light intensity. However, the current change is very low due to low mobility of the P3HT OFET.

Fig.S5: Single exponential fitting of the decay transients measuring readout time for the integrated device for two OPDs: (a) Pixel1 with d=200 nm and (b) Pixel2 with d=500 nm. The small difference in read out time is due to the decrease in junction capacitance of the OPD when thickness is increased.

Fig. S6: Metal-Insulator-Semiconductor - Charge Extraction using Linearly Increasing Voltage (MIS-CELIV) measurements to obtain the hole mobility and charge transit time1. The device structure is ITO|PEDOT:PSS(40 nm)|BHJ(200 nm)|LiF(100 nm)|Al(70 nm).

Experimental Section:

Patterned ITO coated substrates were cleaned and coated with aluminum gate electrodes by physical vapor deposition using a shadow mask. The Al coated substrates were immediately exposed to pure oxygen plasma for 15 min. This was followed by immersing the substrates in THF:EtOH (1:1) solution containing Octadecylphosphonic acid (OPA) at 60˚c for SAM formation. The FET active layer PBtzOR was spin-coated from 7 mg/ml chlorobenzene solution on the SAM functionalized substrates. Gold source-drain electrodes (50 nm) were subsequently coated by physical vapor deposition. The gold electrode was serially connected to the ITO during the evaporation process. This was followed by selectively exposing the ITO coated region to mild air plasma for 5 minutes to clean the surface for OPD fabrication. A ZnO buffer layer was spin-coated on the ITO at 3000 rpm and annealed at 150˚c for 15 min. Soon after, the photodiode active layer (PBDTTT-CT:PC71BM) was spin-coated at 1000 rpm for 60 sec. Using a shadow mask, the counter electrode MoOx/Ag (8/100 nm) was evaporated thermally to complete pixel fabrication.

References:

1A. Armin, G. Juska, M. Ullah, M. Velusamy, P. L. Burn, P. Meredith, and A. Pivrikas, Advanced Energy Materials 4 (4) (2014).