Pda36a

Voltage transients were measured in atmosphere. The same LEDs used in the charge extraction experiment were used to obtain the voltage transients. The LEDs were powered by a Hewlett-Packard 8114A pulse generator, and the voltage transients were recorded by a Tektronix TDS5104B oscilloscope. The spectrum of each LED was measured using an Ocean Optics HR4000 spectrometer and the power output of the LEDs was recorded using a Thorlabs PDA36A amplified silicon photodetector. The values of L_D obtained were (11.5±1.2) nm for C₆₀, (8.5±1.0) nm for SubPc, (4.7±0.7) nm for H₂Pc, (2.8±0.4) nm for MgPc, (4.7±0.7) nm for CuPc, and (4.6±0.9) nm for PbPc. Values of L_D for a single device were determined by averaging three to five voltage transient measurements using LED intensities ranging from about 10 to 150 mW cm⁻². Reported L_D values are obtained by averaging measurements of twelve C₆₀, twelve SubPc, six H₂Pc, three MgPc, fourteen CuPc and three PbPc devices. The error is the standard deviation across all devices and LED intensities.

Fluorescence was monitored with a custom-designed two-photon microscope (Fig. 1b). The embedded zebrafish were placed under a water immersion 40x/0.8 numerical aperture objective (OBJ1; LUMPlanFl40XW/IR2, Olympus) that focused the excitation light from a MaiTai HP laser (Newport). Multiple horizontal planes through the cerebellum were imaged at a 2 Hz scan rate (512 × 512 pixels, ~3 planes per fish). Emitted light was collected through the 40x objective, and reflected by two dichroic mirrors (DM1, 720dcxruv; DM2, 565dcxr; Chroma Technology) into separate red (F2; ET605\70m-2p, Chroma) and green (F3; ET525\50m-2p; Chroma) channels. Fluorescence signals were detected and amplified by photomultiplier tubes (PMTs, R3896; Hamamatsu), while scattered light from the focal plane was detected by a substage photodetector (PD, PDA36A, Thorlabs). Signals from the PMTs and the PD were acquired by ScanImage⁹³ to generate fluorescence and contrast images of specimen in the focal plane.