How to save chararcter matrix in single column in NetCdf file?

I have a character matrix which can be saved in a netcdf file. I am trying to save it in a single column but it is saving it in different rows and columns. Can someone suggest how to save it in a single column?

char_mat =['101670';'101670';'101670'];

nccreate('char_files.nc','char_mat',...

'Dimensions', {'x',size(char_mat,1),'y',size(char_mat,2)},...

'FillValue','disable','Datatype','char');

ncwrite('char_files.nc','char_mat',char_mat);