III-Nitride emitters span the entire visible wavelength range into UV, fulfilling numerous applications in general lighting, display technology, and sensing. However, emerging applications including water disinfection and visible light communications demand higher efficiencies than are currently achievable in III-Nitride LEDs and laser diodes. Losses in such devices stemming from resistive layers and contacts, uneven carrier injection, and poor light extraction limit wall-plug efficiencies at the deeper UV-C wavelengths, ~260 nm, to < 10%. This work introduces several transport-based strategies for improving wall-plug efficiency in III-Nitride emitters. Much of the previous research efforts, in contrast, have focused on improving light extraction efficiency at the expense of electrical efficiency. Optimizations for dopant incorporation and analysis of carrier activation are explored in high-Al n-AlGaN and p-AlGaN in order to maximize the conductivity of these layers. Additionally, p-InGaN contact layers and tunnel junctions are employed in place of p-GaN contact layers, improving p-contact resistances by ~2 orders of magnitude. A novel approach involving the use of bottom-TJ geometry, which mimics N-polar polarization field orientations on metal-polar substrates, is shown to improve wall-plug efficiency in visible laser diode structures by ~1.3x, at no cost to light extraction efficiency. Additionally, the efficacy of this strategy in UV emitter structures is demonstrated in simulations. New devices making use of bottom-TJ geometry, such as the light-emitting field-effect transistor and electrically pumped single photon emitters, are explored. The results presented in this work are beneficial for the development of efficient UV-C laser diodes.