I assume that by “rows” you mean that you have joined the cells in series.
Voltage adds as you place solar cells (or indeed batteries) in series so, with a row of 9 you generate 9 x 0.5 = 4.5v. About right for charging 2-3 x 1.2v NMH batteries in series through a blocking diode.
The current (amps) adds in parallel, so with on row you still only have 0.5A. That’s actually more than you want for trickle-charging AAs which usually have a capacity of around 2-3000 mAh. Unless you are going to be careful to take them off charge when they are fully charged, you don’t want more that 0.2-0.3 A. So with one row of 9 cells you could charge 2 “rows” of 2 or 3 AA NiMH batteries. So you could trickle-charge 4-6 AAs with your string of 9 solar cells. They would take around 14 hours in full sun.