Hi everyone,
I am trying to switch between 6 pixels of a Perovskite Solar cell that exist on a single slide. I hope this would allow me to measure their voltage and current with one four-wire measurement microcontroller that depends on the cells voltage (Only able to sweep an IV curve if there is light)
I am quite new to electronics, so I need help with the design.
The way the cells work is that there are six negative pixels all connected to one common positive. From pixel to common positive under lighting with a multimeter, I see around ~0.9 to ~1.2 V. In ambient light, there is maybe around ~0.5 V.
Right now, I am using the TMUX1108 multiplexer because as an analog MUX, it supports bidirectional operation and has low leakage current.
I have tried multiplexing separate toy solar cells before, and they work just fine multiplexing the positives from drain to V+ and the negatives all together connected to V- and I- of the microcontroller.
However, what’s confusing me is the perovskites common positive. It means I would have to switch the negatives instead. If this were backwards with a common negative, I’d assume things would work just fine. However, this is what I have to work with right now, and I am just wondering how this would affect the layout.
Currently, I assume each pixel negative on a source line: S1, S2, S3, S5, S6, S7.
Microcontroller I- V- to drain. V+ V- to common positive.
Pulling A2, A1, A0, EN high or low to switch/enable circuit.
My questions are:
I apologize if I cannot provide more about the microcontroller as it is confidential. Therefore, just assume it works as a typical four-wire IV measurement setup.
Spare me as I am trying to learn! Thank you!
I am trying to switch between 6 pixels of a Perovskite Solar cell that exist on a single slide. I hope this would allow me to measure their voltage and current with one four-wire measurement microcontroller that depends on the cells voltage (Only able to sweep an IV curve if there is light)
I am quite new to electronics, so I need help with the design.
The way the cells work is that there are six negative pixels all connected to one common positive. From pixel to common positive under lighting with a multimeter, I see around ~0.9 to ~1.2 V. In ambient light, there is maybe around ~0.5 V.
Right now, I am using the TMUX1108 multiplexer because as an analog MUX, it supports bidirectional operation and has low leakage current.
I have tried multiplexing separate toy solar cells before, and they work just fine multiplexing the positives from drain to V+ and the negatives all together connected to V- and I- of the microcontroller.
However, what’s confusing me is the perovskites common positive. It means I would have to switch the negatives instead. If this were backwards with a common negative, I’d assume things would work just fine. However, this is what I have to work with right now, and I am just wondering how this would affect the layout.
Currently, I assume each pixel negative on a source line: S1, S2, S3, S5, S6, S7.
Microcontroller I- V- to drain. V+ V- to common positive.
Pulling A2, A1, A0, EN high or low to switch/enable circuit.
My questions are:
- Is this design correct?
- What values for VDD, VSS, and the logic switches should I have? Would I require VSS in this situation?
- Would unused lines S4 and S8 be GNDed or floating? To which GND?
- Should there be double multiplexers in parallel to separate the voltage and current for four wire measurement precision?
- Would the cells have no reference with the multiplexer if wired this way? Would the common positive or negatives have to be GNDed to the MUX or microcontroller in anyway? Though, I assume the switches in the MUXes behave just like a wire.
- What would happen if there is a dead pixel? I have tried it connecting all the negatives and measuring with no MUX. This would make it parallel, and the voltages zeroed out with the dead pixel yet was fine without it. However, I do not want a parallel circuit here since I want to measure each pixel individually. I assume this pixel might act as a small resistor. Could this somehow short circuit anything if selected?
- How can I mitigate crosstalk?
I apologize if I cannot provide more about the microcontroller as it is confidential. Therefore, just assume it works as a typical four-wire IV measurement setup.
Spare me as I am trying to learn! Thank you!
