Figure 1

(a) Scanning electron microscope images of the patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ sample. The top and bottom right scanning electron microscope images are a magnification of the channels before and after the deposition of NQDs. (b) A schematic of the hybrid patterned device where the channels are partially filled with NQDs. (c) Spectral overlap of the hybrid NQD patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure. The NQD fluorescence (in orange, labeled 1) and absorption (blue solid line) spectrum. The photoluminescence of the quantum wells (in red, labeled 2) and the photocurrent of the $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ device (green dotted line) that shows the heavy- and light-hole resonance.Reuse & Permissions

Figure 2

Time resolved measurements of the hybrid NQD patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure at 25 K. (a) Photoluminescence decay of the bare patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ device before (red dotted line) and after (blue solid line) depositing NQDs. The left-right arrow points to the extended rise time in the hybrid patterned structure due to nonradiative energy transfer. The red dashed line is the fitting result of Eq. (1). Inset: the photoluminescence decay of the hybrid NQD patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure (decay 1) and the photoluminescence decay of the flat $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure (decay 2). (b) Fluorescence decay of NQDs on a glass substrate (black solid line) and on the patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure (red open circles). The red dashed and the black dotted lines are the biexponential fitting curves of the NQD fluorescence on a glass substrate and on the patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure, respectively. Inset: the fluorescence decay of the NQDs on a glass substrate (black solid line) and on the unpatterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ device (pink dotted line).Reuse & Permissions

Figure 3

Photocurrent of hybrid NQD $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure. Pump fluence dependence of photocurrent of the hybrid NQD flat quantum well structure (black squares) and of the hybrid NQD patterned $p\mathrm{\text{−}}i\mathrm{\text{−}}n$ structure (red dots) at 25 K. Dotted red and black lines are fits to the photocurrent signal as described in the text. Inset: fluorescence intensity of NQDs versus pump fluence (green dots).Reuse & Permissions