I have used this one successfully for 48 days in Central Australia, and 17 days in NSW:
https://www.amazon.co.uk/gp/product/B07FMVKHLY/In Central Australia, it produced plenty of power each day to recharge a Samsung Phone (sometimes an A7-2017, sometimes a S10e), a Garmin InReach Mini and a Petzl Bindi headtorch. In NSW there was usually enough power, but when I had three overcast days on the Great North Walking Track followed by a day in shady forest, it didn't produce quite enough power. I had to reduce my power usage by not recording my GPS track.
This panel would work fine with an S9, but it's usually better to charge a small power bank during the day, then use the power bank to charge your devices in the tent at night. A small "lipstick" style power bank will do fine, about 3300 mA-h, because that can replenish all the power you've used up during the day, assuming that you don't run all your devices to zero every day. Most power banks charge well from a variable input, whereas some phones will revert to low-speed charging if the solar panel enters the shade briefly. Mount the panel on the very top of your backpack, not on the back of it. Put the power bank in the lid pocket of the pack, or velcro it to the underside of the solar panel.
I'm on my second one of these, because I caught the cable (which connects the solar panel to the power bank) on some scrub, and the USB socket on the solar panel cracked. For my second panel, I got a very short lead (12cm) so that there was no loop to catch on the scrub.
You need a "Plan B" in case you break your charging system on an extended walk. For me, my "Plan B" is that there will still be SOME charge remaining in my power bank and devices, and I will ration that power for the rest of the trip (e.g. no photos).
If you were a serious photographer, you might need a bigger solar panel and power bank to recharge the camera, but the bigger solar panels unroll into multiple separate sections and bring a whole bunch of additional problems (positioning, robustness, weight and cost).