What is the antenna? I assume there have to be power connectors to take the power from each inidivdual cell, and those would be a few inches long at least. Are you saying those will generate enough voltage to kill the individual cells?
The top of each cell has a conductive layer on it. In some cell designs, this layer has fingers of conducive martial that is visible to the eye. But the entire cell is one giant PN junction that would act as an antenna for the E field. In fact EMP is rated for the rise time and the estimated volts per meter that its E field would induce in any properly oriented conductor.
See slide #2. Note “metallic conducting strips” on graphic of a cell:
https://www.slideshare.net/manavshah735/soldering-of-polycrystalline-silicon-solar-cell