  Electron-hole systems on a Haldane sphere are studied by exact numerical
diagonalization. Low lying states contain one or more types of bound charged
excitonic complexes Xk-, interacting through appropriate pseudopotentials.
Incompressible ground states of such multi-component plasmas are found. A
generalized multi-component Laughlin wavefunction and composite Fermion picture
are shown to predict the low lying states of an electron-hole gas at any value
of the magnetic field.
